Peking — The first encyclopedia in China's millennial history will be a mammoth affair. There will be at least 74 volumes comprising more than a hundred million Chinese characters, the equivalent of 50 million English words. The latest version of the Encyclopaedia Britannica contains 43 million words.
''We want to contribute to China's four modernizations by helping to raise the knowledge level of our young people, especially in science and technology,'' said Jiang Chunfang, president and chief editor of ''The Greater Encyclopedia of China.'' The ''four modernizations'' - China's development program - also include agriculture, industry, and defense.
''We are in a hurry,'' Mr. Jiang continued in a recent interview. ''We started this project in July 1979, and we hope to get at least 70 volumes out by October 1989.'' Mr. Jiang, a Communist Party veteran, is one of China's leading specialists in Soviet literature. For many years he was deputy director of the party's bureau for the translation of the works of Marx, Engels, Lenin, and Stalin. But he maintained there will be a basic difference between the Chinese encyclopedia and that of the Soviet Union, for instance.
''We believe in seeking truth from facts,'' Mr. Jiang stressed. ''We are resolutely against subjectivism. We are not going to put someone in or take someone out because of his political viewpoint, as the Soviets have done. If someone played an important historical role, he will be in our encyclopedia, whoever he may be.''
But Mr. Jiang's viewpoint is clearly communist, and his point of view is that of ''dialectical materialism.'' The encyclopedia's ''objectivity'' is within that context.
There will be a biography of Chiang Kai-shek, Mr. Jiang promised, complete with photograph. Lin Biao, Mao Tse-tung's heir apparent during the early phase of the Cultural Revolution, who was killed in an air crash after his coup attempt failed in 1970, will also be there.
So will Jiang Qing, Chairman Mao's widow, and Zhang Chunqiao, who both are serving life imprisonment terms as leaders of the ''gang of four.''
Bukharin, Kamenev, Radek, and other Soviet leaders purged by Stalin and expunged from Soviet historical records will be taken up by the Chinese encyclopedia, as will such persons as Gao Gang and Rao Shushi, who were purged from the Chinese Communist Party in the early 1950s.
One volume will be devoted to religion. There was an argument among the editors as to whether an article on atheism should be included in this volume. Mr. Jiang decided the proper place to mention atheism should be in a volume on philosophy. He says the articles on the various religions - Buddhism, Islam, Taoism, Christianity - will be objective and descriptive and will be written by adherents of these religions or checked with them.
''We want to avoid any hint of subjectivism or of Chinese chauvinism, any tendency to deny and criticize all Western things,'' Jiang said. ''Our purpose is to introduce the scientific and cultural level the world has achieved.'' The Greater Encyclopedia of China Publishing House is in correspondence with leading encyclopedia publishers around the world. It has a joint venture agreement with the Encyclopaedia Britannica of Chicago, Ill., to translate that company's micropaedia, rewriting and expanding the articles dealing with China and bringing the whole out as an eight-volume set (18 million Chinese characters) in 1984.
The Chinese will have exclusive distributing rights inside China, the Britannica outside China. As for the 74-volume encyclopedia, ''We may expand it if we find we have sufficient staff and there is a demand,'' Jiang said.
This first comprehensive Chinese encyclopedia (a three-volume dictionary-encyclopedia, Cihai, has been available since 1936) will be published , not in alphabetical order, but subject by subject.