The hit of the Santiago theater season is "Three Marias and One Rosa," a biting indictment of the Chilean military junta's aggressive return to free-market capitalism.

Playing to packed houses, it has attracted wide comment because of the vivid script, brilliant acting and devastating portrayal of how unemployment among the poor has torn apart families here.

Furthermore, the play has prompted an extraordinary review of Chilehs "leftist artistic-cultural movement" by the military government, which has become increasingly repressive in recent months after a year of relative liberalization.

The play tells the story of four women who try to eke out a living making hand-sewn tapestries. Their husbands are all umemployed. The women's efforts to sell their wares, which depict the poverty and traumas of their daily lives, allows the play to examine the injustice and absurdities of Chile's current economic and political situation.

In a memo marked "secet" and dated Aug. 22, Gen. Odlanier Mena Salinas, director of the secret police, advised Interior Minister Segio Ferandez that it would be "highly counterproductive" to close down the play because "this would encourage another round of internal and external campaigns aimed at the 'cultural blackout' and 'fascist' measures taken by the Chilean regime." In any case, he added, "the audiences will be relatively small compared to the large metropolitan population" of 3 million.

Instead, Mena suggested that Fernandez initiate "indirect pressure . . . against the organizations which cooperate directly or indirectly in the development, proliferation and expression of artistic groups such as this one" that produced the play.

Mena also suggested that Fernandez create a national cultural fund to encourage artistic activities that "reemphasize traditional values" and he try to influence Chile's mass media either to ignore or comment less favorably about plays, movies, books or other intellectual endeavors considered unfavorable to the government.

The Mena memorandum, a copy of which was made available to The Washington Post, has not been published in Chile, although opponents of President Augusto Pinochet's government are aware of its existence. They say it is another sign of the increasing campaign against intellectuals, artists, writers and politicains that resumed in full force about six months ago.

According to opponents of the government, the first sign of increased harrassment came on May 1, when the police arrested hundreds of persons who participated in demonstrations marking international Labor Day.

The demonstrations were nonviolent although technically illegal since the government bans any "political" activity. The same ban does not apply to groups that gather to demonstrate threir support for Pinochet or the government. Far fewer demonstrators were arrested during similar labor Day demonstrations on May 1, 1978.

In June, the government suddenly closed Hoy magazine, the country's best-selling new weekly, which made no secret of its view that Chile should return to the democratic form of government that preceded the 1973 military coup.

Although Hoy was allowed to resume publication after a two-month lapse, the unexpected action marked the ned of an increasingly tolerant attitude toward the press that began early last year.

In August, Fernandez publicly warned the media that it would have to "accept the consequences" of publishing or broadcasting in full a speech delivered by former president Eduardo Frei, the leader of the suspended Christian Democrat Party.

When one radio station broadcast Frei's speech in full, Frenandez said he would close the station if it did not end the open defiance.

Also in August, Mena's secret police, called the National Center for information, were found by a court to be responsible for the death of a high school teacher who died from physical abuse during five days of detention and interrogation.

The teacher was arrested after allegedly passing out leaflets pringed by the outlawed Revolutionary Movement of the Left and allegedly trying to place a bomb in an unoccupied police van.

While even opponents of the government do not believe the secret police plan to reinstitute the terror tactics that were prevalent during the first years of military rule, the teacher's death demonstrated that the police are still willing to use torture.

In September, the government refused to allow a gathering of democrats to allow a gathering of democrats called the Group of 24 to hold a public meeting to explain a proposed new constitution the group has written.

Fernandez accused the Group of 24 of being "political," which means that its meetings can be banned under national security laws. The constitution is a proposed alternative to an "official" one that the government has announced it will submit to a referendum as a first step toward creating a "guided democracy" by 1986.

Interior Minister Frenandez vowed during an interview last year that the government would allow full discussion and debate of its constitution -- and alternate ones -- before the referendum, which is to take place late this year or next.

In September the government also refused to allow 14 bodies of persons, who were murdered by national police after the coup, to be buried individually by their families. It ordered the bodies, which were uncovered last November in an abandoned mine shaft to be buried in another mass grave.

This decision caused an almost open break between the government and the Roman Catholic church, which is the predominant religion here. The church is led by Cardinal Raul Silver Henriquez, who called the decision "inhuman and cruel."

According to a leading Christian Democrat, Pinochet has ordered a tightening up because the government because frightened of the amount of dissent that surfaced beginning late last year -- a period when the government, under pressure from abroad, did not feel strong enough to move against its opponents at home.

According to this analysis, Pinochet has felt stronger since a dispute with neighboring Argentina over land and sea rights near Cape Horn was sent to the Vatican for papal mediation.

Also, some observers believe, the government thinks it can escape serious U.S. sanctions despite the failure either to extradite or try three secret police officers charged in the United States inthe assassination of exile official Orlando Letelier.

At the same time, this Christian Democrat said, the government feels increasingly vulnerable because of its economic policies, which have reduced inflation substantially and promoted economic growth but have not made a dent in the unemployment rate of at least 15 percent in Santiago and probably higher elsewhere.

Supporters of the government do not challenge the assertion that there has been a crackdown during the past six months. Members of the government agree that the temporary closure of Hoy, for example, was a serious mistake that further blackened the junta's image abroad and increased the magazine's influence and circulation.

Government supporters tend to say that the parties, union and the press took unfair advantage of last year's opening and had to be reined to because the government has no intention of moving back to democarcy faster than its own timetable calls for.

The "mistakes" tend to be blamed on Pinochet. Even supporters of the military say he has become increasingly powerful -- and increasingly willing to use his personal power, often arbitrarily -- now that he has swept aside those within the military who opposed him.

Civilian supporters of the government justify its continued existence because of the economic strides that have been made and the need, they say, to retian a firm government for several more years to give the free-market system here a chance to demostrate its benefits to the poor.

Plays such as "Three Marias and One Rosa," that dramatize the plight of the umemployed and the benefits that have accured to the rich, incite opposition to the economic program. According to many observers, including Mena, this must be controlled if the government is to carry out its political and economic plans.