Gorbachev gets support - and a taste of Soviets' deep concerns. SOVIET CONFERENCE

The just-completed Communist Party conference marks a watershed in the history of Soviet reform. By sleight of hand and force of personality Mikhail Gorbachev has shifted the center of attention to the reshaping of political institutions. A clear timetable has been laid out for the changes (see Page 5).

But the conference, which ended Friday, also revealed the remarkable diversity of political views within the Soviet Communist Party.

The conference was a personal victory for Gorbachev - and arguably a more discreet victory for the architect of radical reform, Alexander Yakovlev. Gorbachev proved wrong pessimistic predictions that the debate would get bogged down in wrangling and recriminations.

It was, however, a paradoxical victory. He championed democratization and free debate at the conference - exemplified by the remarkable exchange between Central Committee maverick Boris Yeltsin and party No. 2, Yegor Ligachev.

But Gorbachev achieved his political coup by simply not giving any advance notice of the main element of his reform program. The key idea in his report to the conference - the proposal for a presidential system of government - was floated in the Soviet news media two weeks before the conference began. Usually reliable sources say many members of the Communist Party Central Committee found out about it at roughly the same time.

There was at least one other paradox: while the conference gave Gorbachev a mandate for reform, it also revealed a groundswell of apprehension among rank-and-file party members about many of the byproducts of reform.

The next stage of reform will be particularly delicate. Gorbachev's success so far has been partly due to the force of his own personality, and partly to the elitist nature of the Soviet system. This has given him the power to conduct a revolution from above. But now he will be trying to dismantle part of the system that gives the party its authority. Much of the day-to-day power will, in theory, shift to the soviets (the representative bodies or parliaments) from the locality level up, which have hitherto been rubber stamps.

As he transfers power to the soviets, Gorbachev will have to steer carefully between party officials keen to hold onto privileges, and radical activists who want to limit the party even further.

The reaction of the rank-and-file conference delegates to many of last week's debates indicates that many Communist officials are already dismayed at the erosion of the party's authority and social standing. Delegates' irritation with the outspokenness of the media was so strong that a relatively conservative editor, Viktor Afanasyev of Pravda, was finally led to comment on the ``perceptible hostility'' toward the media in the conference hall.

Several conservative speakers warned of the dangers of creeping ``anarchy'' in Soviet society. They never explained what they meant, but they got warm applause each time.

The anxiety of many delegates over the speed of political change may help explain why Gorbachev needs Mr. Ligachev in the top leadership. Ligachev's speech to the conference was an eloquent statement of the conservative line.

He called for both ``determination'' and ``circumspection'' in proceeding with reforms. (The Soviet satirical machine did not let this particular paradox lie quietly for long: What he means, a student quipped Saturday, is that ``you have to move determinedly against those who are not circumspect enough.'')

Ligachev expressed deep unhappiness at the radical press and indignation at the questioning of party officials' privileges. He was concerned that the reassessment of the Soviet Union's totalitarian past would lead to a complete repudiation of Soviet achievements.

Most strikingly, he denied that there were any splits in the Communist Party leadership. Anyone who claimed there were splits, he implied, was bringing pleasure to the country's bourgeois enemies. His claim that the party was not divided over reform seemed manifestly at variance with comments by Central Committee officials that an ``intense political struggle'' is taking place within the party.

Ligachev's speech was nonetheless well-received by party officials inside and outside the conference hall. (This correspondent listened Friday to extracts of the speech on a car radio belonging to a group of security men. They were vocal in their approval.) This leads to the conclusion that Gorbachev needs Ligachev to reassure the party structure that reform is being kept within tolerable limits.

The conference also highlighted a third, lesser strain in Soviet politics: the populism exemplified by Mr. Yeltsin. Although Yeltsin's speech at the conference won him little support from delegates, there was no sign that he had lost any of his popularity on the streets. The day after the meeting, some demonstrators from nonformal groups wore Yeltsin lapel buttons, some carried a banner in his support. And one passerby commented sarcastically on one charge leveled at Yeltsin during the conference: his over-rapid hiring and firing of officials.

``So he made life a misery for the officials,'' said the man, a lathe operator. ``They make life a misery for us all the time.'' Timetable for change

``All power to the soviets!'' shouted demonstrators the weekend before the 19th party conference began. ``But to new soviets, elected by early elections. We can't wait four years till the next general elections: reform will be dead by then.''

The demonstrators, who support reform but are suspicious of the Communist Party bureaucracy, seemed uncannily clairvoyant in their demands. On Friday, the conference outlined changes:

Fall, '88: New elections to Communist Party organizations. By year's end: reorganization of party apparatus.

Fall, '88: New legislation and constitutional amendments reinforcing the power of the soviets (parliaments).

April, '89: Elections for Congress of People's Delegates, new supreme body called for under reforms. This will elect a president (likely Gorbachev) for a maximum of two five-year terms.

Fall,'89: New soviets elected on republican, regional, and local level.