In the veiled world of palace intrigue that passes for politics here, the appearance of the president's mother as matron of honor in his recent wedding was imbued with as much significance as a major Cabinet shakeup.

"Mama Simone," as the widow of late President Francois "Papa Doc" Duvalier is known, is believed often to be at odds with her 28-year-old son, current President-for-Life Jean-Claude Duvalier. Before his latest romance led to marriage, she was know to have driven several of his girlfriends out of town.

This time, however, Duvalier reportedly met the usual matriarchal maneuvers with the threat that, were he thwarted, he would abdicate and he and his beloved would leave the country. The elder Mrs. Duvaliers acquiescence and gracious participation in the nuptials signed a significant victory for Jean-Claude in Haiti's on-going power struggle.

The struggle appears to have little to do with politics. "There are no factions here, no real political parties, no tendencies," said one influential Western diplomat. "There are just arguments over control."

Recently, however, new elements have been introduced into the Haitian power equation, giving some substance for the first time to the battle for control.

International donors, who supply what for this small country are massive amounts of foreign assistance, have become concerned over alleged human rights violations. At the same time, Haitian peasants suddenly have begun to ask what their government is doing for them.

These developments have given rise to a feeling here that a politcal crossroads has been reached and that a new direction will have to be plotted.

On one side of the power struggle is Jean Claude, who at 19 took over after his father's death in 1971 in a sort of regency system, where he served as a dynastic figurehead while the country continued to be run by Papa Doc's old guard. As he has grown to adulthood, however, the young president has begun to assert himself and gather his own team around him. y

On the other side, remains the rightwing old guard itself, known collectively by local wags as "the dinosaurs." In addition to Mama Simone, old guard leaders are considered to include National Police Chief Jean Valme and Mrs. Max Adolphe, the local boss of the country's central region and head of the Volunteers for National security, the successor to Papa Doc's feared Tonton Macoutes paramilitary organization.

Among this cast of characters, control shifts in ways that can only be spotted by diligent collectors of clues such as the wedding, new Cabinet appointments attributed to a power play by one group or the other and obscure references in official speeches.

Traditionally, the control coveted by the competing power groups does not involve the loyalty of the Haitian masses, which by and large have been docile under the Duvalier dynasty and which in any case have no option to vote the lifetime leader out of office.

"This government has never been in the habit of doing anything for its citizens," said one local observer. Haiti remains at the bottom end of most lists of intenational statistics such as per capita income, infant mortality, life span, nutrition and literacy.

Even if it were so inclined, there is little the government could do. Haiti is vastly overcrowded and has not a single natural resource of substance beyond masses of workers who frequently are too malnourished to labor effectively. Reformers who manage to attain positions of governmental power find they have little but themselves to depend on. One current Cabinet official said he began his first day in office by giving all employes a literacy test.

Control in Haiti rather involves control over what income the government does have. Much of that income is deposited into bank accounts over which there is no central accounting.

"There is little question," the diplomat said, "that this is a society made up of exceedingly selfish people whose politics revolve around money and rackets."

But while the basic structure of Haitian government has changed little, the power drift from one group to another has brought what, for Haiti, are fairly substantial changes in the past 18 months.

It began in early 1979, when opposition candidates for the first time in 22 years of Duvalier rule challenged government choices in elections for the traditionally rubber-stamp Congress. Some were arrested, although one candidate in the northern Cape Haitien District actually won a seat following what were nearly unprecedented popular protests there.

Other similar but unsuccessful protests led to a general clampdown and increased repression against political and press activity, which continued until near the end of the year.

Then, on Nov. 9, thugs believed to be secret police agents broke up a human rights meeting here and struck an American diplomat who was attending as well as a number of Haitians. The United States, which directly and indirectly provides a substantial portion of Haiti's aid budget, expressed "deep concern." The U.S. ambassador said he was "appalled."

That incident, coupled with charges against the government of violating human rights, dramatized by thousands of escaping "boat people," broke the spell of repression. After the November human rights meeting, "somebody obviously felt they had gone too far," one observer said, "and things started turning around."

Within days, former Haitian Ambassador to the United States Georges Salomon, considered part of the palace group close to Jean-Claude Duvaller, was appointed foreign minister. One of his first acts was to establish a human rights office, the first the government ever had, to "assist local and international organizations investigation human rights violations in Haiti."

By December, a journalist's commission had been appointed to revamp a harsh press control law imposed only three months earlier and succeeded in getting its most draconian provisions excised.

The leader of an embryonic opposition party, an unsuccessful candidate in the 1979 elections arrested for calling for Duvalier's overthrow, was released from jail.The newspaper Le Petit Samedi Soir, Radio Haiti and Radio Metropole, which constitute the opposition or at least nongovernment media here, began increasing coverage of citizen complaints and commentary while still stopping far short of overt criticism of the government.

Two weeks ago, the Haitian Congress held its first-ever debate on the alleged mistreatment of Haitian migrant workers in the Dominican Republic, acceding to demands by Alexander La Rouge, the sole non-Duvalier representative.

The changes appear due less to a change of heart on the part of Duvalier than to simple pragmatism, as continuing charges of official corruption and human rights abuses threaten to cut seriously into Haiti's chief source of funds -- international foreign aid.

At the same time, Duvalier appears trying to build his own constituency apart from the old guard "dinosaurs" by allowing limited popular freedoms and addressing the society's most blatant deficiencies. "He wants to be loved," said on cynical Haitian.

The results so far are still up in the air. What the government terms its "liberatization" program appeared to have little effect on a recent U.S. court decision in which at least the possibility of political asylum was opened to Haitian boat people because of what a Miami judge termed the "brutality" of their own government.

Last month, an appropriations subcommittee in the House of Representatives voted to eliminate $2 million from an administration-proposed $7.2 million in economic aid for Haiti, because of "the government's tragic disregard for the well-being of its people and . . . for brutality and corruption in Haiti."

Neither has the domestic path been easy for Duvalier. His father was known for his ability to sniff out and quash even rumblings of possible coups within an armed forces that resented his power and the Tonton Macoutes. Today, the mostly conservative military is believed unhappy with the current president's liberalization, no matter what his reason for it.

At the same time, what is known as the "ratiionalization" program -- the transfer of government funds into public accounts to appease international donors worried about corruption -- is causing its town brand of internal upheaval.

Duvalier "has a big problem and nowehere to go," said one local analyst. "If he stops corruption, he has a big problem on the right. If he doesn't, he has a big problem with the foreigners."

There is a consensus among palace watchers that the liberalization -- both politically and fiscally -- will continue, however. This is because of the longterm economic necessity for it and above all because Jean-Claude holds the trump card, which is believed to have much to do with the success of his wedding plans.

He carries the Duvalier name, something that even his liberal critics agree is what holds this country together through lethargy, poverty and long habit. "If he's gone," the Haitian analyst said, "the whole structure collapses for all of them."