The Reagan administration's efforts to stabilize and reform Bolivia's military government through close ties and quiet pressure so far have failed to curtail significantly the human rights violations and widespread narcotics trafficking that have isolated this turbulent country.

The United States renewed full diplomatic relations with Bolivia in November after a 16-month freeze begun when the military interrupted the electoral process and overthrew a civilian government. The thaw followed an internal military shuffle that left a supposedly reformist general, Celso Torrelio Villa, as president in place of discredited Gen. Luis Garcia Meza.

With the strong urging of U.S. officials, Torrelio announced broad plans to return the country to democracy and crack down on a drug industry believed to supply at least half of the illegal U.S. cocaine trade.

Since then, however, Torrelio, 48, a bulky former Army commander, has shown himself to be indecisive and politically too weak to carry out his pledges, according to military figures and Bolivian analysts here. While government repression of political opponents has noticeably decreased, widespread arrests and torture continue, as do bombings and shootings by paramilitary death squads bold enough to announce themselves in newspaper ads.

Meanwhile, Torrelio's government has not taken real action against either the cocaine trade or the dozens of high military and former government officials allegedly tied to it. Informed analysts predict that Bolivia will produce well over 200 tons of pure cocaine this year, of which 90 percent--more than $1 billion worth--will enter the United States.

U.S. officials, including the new ambassador, Edwin Corr, have continued to support Torrelio as the most moderate and honest alternative among the tangled array of competing military leaders. Hoping to quietly push the military government into more reforms, U.S. officials hint that "positive acts" by the government will lead to a resumption of some of the still-suspended U.S. aid the nearly bankrupt Torrelio government desperately needs.

The relative lack of progress has frustrated Reagan administration policy makers, who have tried to demonstrate that strong ties and quiet talks are more effective in improving South America's authoritarian governments than the outspoken criticism of the Carter administration.

The awkward position of U.S. officials as suitors of a willing but sometimes unable government was evident this month when, just as the La Paz papers were trumpeting an optimistic Reagan administration report on human rights here, more than 20 labor leaders were arrested. One was said by church sources to have been tortured with electricity.

"You see how it is," said a human rights official. "Even when one hand of the government wants to do right, it can't control the other."

U.S. officials were more successful last year in improving relations with two of Bolivia's military-ruled neighbors, Argentina and Chile, by ending a policy of voting against their loans in international banks and by obtaining removal of congressional bans on arms sales.

Bolivia seems a less likely place for strategic U.S. interests. Its 5.5 million people, mostly of Indian descent, are among the most impoverished in Latin America. They tend tiny farm plots or raise llamas and alpacas in high, wind-swept Andean villages unchanged for centuries.

Bolivia, in the center of South America, is the size of California and Texas combined, rich in tin and natural gas. Ever since Che Guevara unsuccessfully attempted to lead a revolution in the country's eastern jungles, U.S. policy makers have maintained close ties with Bolivia's conservative military leaders.

What held up immediate Reagan administration conciliation with the government last year, according to sources here, was wide international and congressional opposition to the government of Garcia Meza, labeled by human rights groups as one of the most corrupt and violent of the almost 200 presidents and dictators in Bolivia's tumultuous history.

Shortly after completing a July 1980 coup that resulted in an estimated 500 deaths and 2,500 jailings, Garcia Meza, a career Army officer with strong authoritarian views, launched what critics said was a violent campaign to exterminate Bolivia's well-developed and generally left-of-center political parties and labor organizations.

In addition, according to foreign officials and Bolivian military officers here, Garcia Meza, the chief of security forces, Col. Luis Arce Gomez, and dozens of other military officials quickly grew rich from the country's cocaine trade, smuggling operations and illegal sales of mineral contracts to foreign investors.

Finally, as the continuing cutoff of about $125 million in U.S. economic aid and an embargo by other major international lenders brought the military government to the point of bankruptcy, a rebellion by reformist military officers broke out in one of the country's key garrisons.

After a month of confused maneuvering, a compromise was reached in September: Garcia Meza was removed and Torrelio, an officer widely considered free of drug traffic ties but also a loyal member of Garcia Meza's Cabinet, took over.

Garcia Meza was slow to move out of Torrelio's way--he stayed in the presidential palace a month--and civilian opposition leaders were soon saying that the change in the government had only been cosmetic.

Before the end of September, however, two high State Department officials were in La Paz to meet with Torrelio, carrying, one observer said, "a whole script of things to tell him."

Torrelio's government plan, announced over the next month, covered all the priorities set forth by the Reagan administration: an attack on the cocaine trade, improvements in human rights, remedies for Bolivia's collapsing economy and a plan for democratic elections, which Torrelio has proposed to hold in three years.

Since then, however, the measurable results of those proposals--particularly on the high U.S. political priorities of human rights and cocaine traffic--have been mixed.

Human rights groups and opposition leaders here agree that the climate of military oppression has slackened since Torrelio took office. Church sources recorded 347 political arrests and three documented killings by Army or security forces in the last six months of 1981, but this was an improvement, they said, from the massive operations of Garcia Meza's intelligence apparatus.

At the same time, the Torrelio government has retained a curfew and prohibitions on most political and labor activities, although the restrictions on labor are slowly being eased. About 3,000 political detainees have been sentenced after their release to live in a city named by the military and sign in with the police as often as three times a day, rights organization leaders said.

Moreover, Torrelio reportedly has not halted abuses by the government's intelligence service, which kept the director it had under Garcia Meza.

Two peasant leaders charged in an interview that they recently were held secretly by the intelligence service for more than a month and tortured with electric shocks after being drenched in water and strapped to iron bedframes.

"After the torture sessions, when we are in jail on Christmas, we heard them announce over the radio that they were holding no political prisoners," said one.

Torrelio's defenders say he is not personally responsible for the continuing torture or attacks on opposition military figures and labor leaders and simply does not have the political strength to stop those who are.

"Torrelio is like a bull, but he's an indecisive bull," said an American here. "He hasn't consolidated himself enough to really act. And the odds of Bolivian history are against him."

Similar explanations are given for Torrelio's failure to begin major efforts to halt the country's cocaine trade or move against any of the dozens of military officers charged by reformist colleagues with benefiting from it.

Government opponents say, however, that Torrelio's inaction on these issues--for whatever reason--means that the character of the military government has not changed since Garcia Meza was ousted.