BEIJING, OCT. 25 -- China opened its first Communist Party congress in five years today with Premier Zhao Ziyang predicting that his country will gradually catch up with the capitalist nations through an economic "revolution" that stresses practical results.

Zhao went on the offensive in today's speech, making few concessions to conservative critics of economic change, and appearing to seize the high ground in an effort to revitalize a reform program that has faltered in a number of areas.

Speaking in the Great Hall of the People against a backdrop of massive red flags and a huge gold hammer and sickle, the premier, who is expected to be named party leader following the eight-day congress, proposed political reforms to decrease party interference in government activities and limit the powers of entrenched party bureaucrats who resist new ideas.

For the first time in modern Chinese history, Zhao also proposed the establishment of a civil service system that would promote officials on the basis of examinations and job performance. Such a system would be unprecedented among communist countries and is aimed at making the world's largest and perhaps most cumbersome bureaucracy more efficient and responsive to reforms.

In delivering the keynote address at the opening session of the party's 13th national congress, Zhao defended the reforms that some critics have described as capitalistic, such as the introduction of stocks and bonds and a reliance on market forces. He urged his fellow Marxists to "widen their vision, develop new concepts and enter a new realm."

"We shall gradually put an end to poverty and backwardness," declared Zhao, arguing that the main sources of resistance to reforms and China's open-door policy were deep-rooted, "leftist" habits of thought. China has to keep itself open to the outside world to close the gap between it and developed capitalist nations, he said.

Zhao said China intended to double its gross national product by the end of this century, enabling the Chinese people to attain "a fairly comfortable life."

By the end of the century, China's main industries will come fairly close to the technological level achieved by the developed nations in the 1970s or early 1980s, he said.

Whether Zhao and his mentor, paramount leader Deng Xiaoping, have the political power to impose further major reforms remains to be seen. But the speech by Zhao indicated that with Deng's support, he and his reformist allies have taken the initiative on both the economic and political fronts.

Today's meeting began when Deng, 83, looking fit and tanned and wearing a gray Mao suit, strode into the cavernous hall to the applause of the nearly 2,000 delegates.

He was followed moments later by the ailing Chen Yun, 82, a conservative leader who has been Deng's most eminent rival for influence. Chen favors more centralized control over the economy than Deng does and is respected by Marxist ideologues who fear the "capitalistic influences" that have accompanied economic reform.

Supported on both sides by aides, Chen moved with painstaking slowness to the dais and seated himself to the right of Deng.

For party members looking for symbols of reformist vigor, the contrast between Deng and Chen must have been striking. Deng seemed to emanate strength and confidence as he sat back, followed Zhao's speech from his copy of the text, and occasionally puffed on a cigarette. During much of the speech, Chen's eyes appeared to be closed because of his weakened physical condition. Apparently tiring, Chen left the dais more than an hour before Zhao finished his nearly 2 1/2-hour address to the congress.

The congress was the first to be open to the western press since the communists took power in 1949 and was broadcast live throughout the country. Many Chinese in Beijing, however, said they did not watch the telecast because they felt the congress would have little impact on their lives.

Zhao attempted to placate critics who worry that his reforms depart too much from Marxism when he spoke of a need to combat excessive consumption and to pursue "plain living and hard struggle."

He stressed a need to maintain the party's leadership, increase grain production, and counter corruption by officials who use their positions to make personal profits -- all themes dear to the hearts of party traditionalists such as Chen Yun.

But the pragmatic Zhao, dressed in a well-tailored gray western suit, light blue shirt, and red silk tie, stressed repeatedly that economic production is the main test of the country's policies rather than abstract theories. "Judging life by abstract principles or utopian models instead of by the growth of the productive forces will only discredit Marxism," said Zhao, to the applause of delegates.

He advocated further departures from a Soviet-style centralized economy when he defended China's relatively small but growing private enterprises. He also advocated a competitive contracting system for industrial projects and renewed a call for the reform of China's irrational pricing system.

In addition, the premier said, China should "improve the investment environment for foreign businessmen."

He said officials should be promoted to important positions if they perform well, but not if "they indulge in empty talk and do nothing practical for socialist modernization."

The economic reforms that are transforming the country amount to "another revolution," he said. In an unusual display of public praise, he gave Deng much of the credit for the country's reforms and opening to the outside world.

Addressing political reform, Zhao called for limits on the role of the party's Central Commission for Discipline Inspection, headed by Chen Yun. The commission, which has been a stronghold for conservatives, should not concern itself with breaches of law that fall under the jurisdiction of legal agencies, he said. Instead, the commission "should concentrate on fostering a fine party conduct and a strong sense of discipline," he said. He called for the decentralization of the party and said party departments that overlap with their counterpart government departments should be abolished.