SANTIAGO, CHILE -- Six months after Augusto Pinochet surrendered the presidency, Chile's new civilian government finds itself hemmed in by the restrictive constitutional and legal framework that the general left behind.

President Patricio Aylwin, a Christian Democrat elected by a center-left coalition, has had to try to get his legislative program through a Senate that Pinochet made sure would be effectively controlled by the right. The president has to negotiate monetary policy rather than simply mandate it, because Pinochet made the Central Bank autonomous.

Aylwin is unable to hold the armed forces accountable for human rights crimes during the 17-year dictatorship because of an amnesty law that Pinochet imposed -- and because of Pinochet's continued presence as head of the army. Aylwin has no authority to remove Pinochet or any of the other top military commanders, and he is stuck with a level of military spending that leaves less than he would like for the new social programs that his constituents expect.

Aylwin generally has received high marks from across the political spectrum for easing the country cautiously through the transition to civilian rule. He has reassured the right by holding to his promise to continue the former government's free-market economic policies, and pleased the left with a tax-reform project and planned initiatives to spend more on education and health. The diverse coalition that elected him remains intact, and Aylwin's popularity hovers near 70 percent, according to polls.

But now the government finds itself straining against its legal limitations, and reform of the constitution is becoming a priority.

"We've made the psychological transition, and now we're moving into the second stage, which is constitutional reform and human rights," said Sergio Bitar, secretary general of the Party for Democracy, one of the most prominent leftist elements of Aylwin's coalition. But "overhead there's our sword of Damocles -- all the social demands."

Pinochet's constitution allowed his regime to appoint nine senators as a bulwark against change. Although Aylwin has had some success in working with the appointed and elected conservatives in Congress -- he got through a tax package expected to raise $700 million annually -- the administration wants to eliminate these appointed seats.

Ultimately, the government wants to change the constitutional provisions that effectively make the armed forces self-governing, a kind of parallel power outside civilian control. For example, Aylwin lacks the power to remove the commanding officers of the service branches. Pinochet can remain as head of the army nearly eight more years.

Human rights has proved to be a frustrating issue for the new administration. Not even the Pinochet regime's bitterest opponents argue that there is much chance of bringing Pinochet or other military officers to trial for the killings and torture committed during the military government. But Aylwin pledged that his government was committed to learning the truth of what happened during those 17 years.

Mindful of the wrenching, drawn-out process of investigations and trials that neighboring Argentina went through after returning to civilian rule, the Aylwin administration had planned to take only a year to deal with human rights. That timetable is likely to slip.

In June, a nine-member Truth and Reconciliation Commission named by Aylwin began gathering evidence on political killings and disappearances. But the work is hampered by an amnesty law that Pinochet left behind, which some interpret as barring not only prosecutions but investigation as well.

The law, covering acts committed between 1973 and 1978 -- the period when most of the human rights violations occurred -- recently was upheld by the Supreme Court.

Meanwhile, the issue has become more emotional with the finding of several mass graves where the military buried suspected leftists who were executed following the 1973 coup that overthrew Socialist president Salvador Allende. Estimates of the total number executed in the weeks after the coup range up to 2,000.

On this issue, the Aylwin coalition is far from monolithic -- those who supported Allende want the government to push harder. The Roman Catholic Church also has been vocal in demanding action.

Chile's economy is by most measures the healthiest on the continent. And the Aylwin government has worked with the Central Bank to slow economic growth, which amounted to nearly 10 percent last year and threatened to produce annual inflation of 35 percent. The government charges that the Pinochet regime overheated the economy to aid its favored candidate in last year's presidential vote, Hernan Buchi.

Fear that the monetary belt-tightening undertaken earlier this year might cause a recession led the Central Bank to announce this week that it is "softening" its grip. This year the economy is expected to grow only about 2 percent, with inflation of 25 percent.

"The task now is the reactivation of the economy and the strengthening of investment," Finance Minister Alejandro Foxley said last week. "We're entering a phase of sustained growth."

Revenues from a new value-added tax and increases in some other taxes will allow more funds for social programs next year, he said, particularly health and education.

Pinochet remains a major political presence, despite attempts by some rightist parties to distance themselves from him. Some analysts say that in his frequent sharp criticism of the new administration, he is trying to keep open the option of running for president in 1993.

Last week, in an off-the-cuff outburst, he indicated that he saw a move underfoot to change the Chilean army in ways that he said would make it resemble that of West Germany. The German army was once "invincible," he said, but now is "an army of marijuana smokers, drug addicts . . . homosexuals and union activists." An army spokesman quickly retracted the remarks.