A confidential Communist Party document, prepared by a special high-level commission, faults past Polish leaderships for losing touch with the people and blames party bosses for the social crises that have periodically shaken this nation since Communist rule began after World War II.

Contrary to the official propaganda, which attacks the West and internal "counterrevolutionary forces" for sowing unrest, the 157-page report says the country's recurring upheavals have resulted primarily from party leaders shutting themselves off from competent advisers and the interests of common people.

Though the study might be read as an elaborate justification for the military having wrenched power from the party when martial law was imposed in December 1981, the background to its preparation suggests the report is best viewed in the context of a current effort to resolve the party's longstanding factional disputes.

Coming to light now, as Poland's Communist officials plan to reset the party's ideological course, the study reflects a continuing behind-the-scenes clash between the hard-line and more reform-minded wings.

It pointedly accuses the leadership of having responded only superficially to Poland's social ills and obvious need for economic reform. Allowed to accumulate, these problems fed the tensions that exploded in the strikes of August 1980 when the now-banned independent trade union Solidarity was born, the report says.

"In summary, it can be stated that the fundamental reason for the social crises in the people's Poland was the manner of governing and the relation of the authorities to society," says a first draft of the study, which has been made available to some westerners.

Ordered in the summer of 1981 during a heady period of self-criticism and budding democracy at the Polish United Workers [Communist] Party's ninth extraordinary congress, the draft report took a year to complete by a 34-member blue-ribbon commission. Its exact status now and likely impact on party policy are unclear.

Party spokesmen did not respond to questions on the subject, and a knowledgeable Polish source said the draft is undergoing major revision.

In general, the first draft represents a victory of advocates of democratic reforms in the party. The government of Gen. Wojciech Jaruzelski, who doubles as first party secretary and prime minister, has publicly backed a moderate reform course.

But a party source said the final draft of the report is apt to be less progressive in outlook than the first. Signaling a setback for the reform wing, Hieronim Kubiak, the liberal academician who chaired the special study commission, was eased from his post as party secretary for education and culture at about the time the first draft was completed last year.

The move was seen then as an attempt to balance the blunting of the party's hard-line faction, which took place with the ouster of Stefan Olszowski from the job of party secretary for propaganda. Both Olszowski and Kubiak remain in the 15-member decision-making Politburo.

The party's 200-member policy-making Central Committee is expected to confront the question of its future political line in a meeting on ideology being planned for the near future.

Depleted and demoralized following the rise of Solidarity, Poland's Communist Party has been slowly reconstituting itself. Official figures show that party membership dropped 779,000, or more than 25 percent, between August 1980 when the workers' strikes occurred and December 1982 when martial law was suspended. It now totals 2.37 million.

Party officials say this thinning out of members and some sober reappraising of past activities have helped strengthen Communist ranks and prepare the party to resume management of the nation.

"Although smaller in number, the party has undergone thorough qualitative changes," said Kazimierz Cypryniak, the head of the Central Committee's organization department, in a recent newspaper interview. "Activity of party members has intensified markedly and the unity of action has strengthened."

But Jaruzelski is reported to have decided to suspend rather than actually lift martial-law restrictions last month after judging that his party still lacked the strength to run Poland.

In its conclusions, the report urges the party to gain wider support among working people and to adopt more democratic features. It recommends democratic elections, a collective leadership style, the rotation of elected jobs in the party and periodic reviews by elected groups of the work of the party's top leadership.

Political reforms, the report argues, are as necessary in Poland as economic ones.

While never questioning Marxism-Leninism as the best system of rule for Poland, the report blames past leaderships for retreating from the principles of socialism and permitting bureaucratic and technocratic forces to take over.

"This centralized system of authority also initiated a tendency to react with brute force to the appearance of the working class," the report says.

Such mismanagement, the report finds, came on top of social changes that were making Poland ripe for revolt. The nation's postwar development from an agricultural country to a modern industrial one, the report says, brought higher educational levels and affluence but also greater public expectations. When the economic goals set by the authorities diverged ever more widely from reality, society's frustrations were felt even more deeply, the report says.

Mounting criticism of the party and government resulted. People resisted attempts by the authorities to make economic ends meet by simply raising prices. Economic distress, not political opposition, the report notes, triggered strikes in 1956, 1970, 1976 and 1980.

Contributing to this recurring sense of unrest, the report goes on, was the fact that underlying tensions were accumulating. The party leadership was giving only partial and superficial treatment to fundamental problems. Economic reform, in particular, was never satisfactorily dealt with, the report says, despite several starts in this direction.

"Appeals to [First Party Secretary] Wladyslaw Gomulka in 1956 and to [First Party Secretary] Edward Gierek in 1970, with whom hopes for reform were connected, reduced periods of acute crisis but also succeeded only in checking temporarily the waves of crises that subsequently occurred," the report states. "For this reason, among others, the crisis of 1980, which could not be checked, proved to be so deep and universal."

Gomulka, forced from power in 1970 by bloody worker riots, died last September. Gierek was toppled in 1980 by the upheaval that produced Solidarity and was later interned along with other senior members of his former government when martial law was imposed in December 1981. He was released from internment last month with the suspension of martial law.

Both men, the party report says, presided over a leadership system that was riddled with incompetence and opportunists and had turned dangerously totalitarian. It was a system closed to proposals of reform because such reforms, the report asserts, threatened changes in rank and losses of privilege for some authorities.

Citing a general regression of democratic practices that separated the party from society, the report says that trade unions were assigned only "facade-like characters" as bosses, the youth movement was homogenized and the Polish parliament lacked sufficient political latitude.

"The protest of the working class in 1980 . . . completely discredited the slogan of the so-called moral and political unity of the nation," the report asserts.

Tensions in East-West relations, although hampering Polish trade and economic development at times, are dismissed as a major cause of Poland's chronic social unrest.

"Equally, there is no proven bond exclusively tying the activity of the political opposition with the genesis of the crises," the study says. "Opposition activity normally aggravated crisis situations but by itself was in no position to provoke them." The role of opposition groups, observes the report, was much larger during the crises than at their outset.