HUNGRY GHOSTS

Mao's Secret Famine

By Jasper Becker

Illustrated. 352 pages. Free Press. $25.

Near the end of 1959, with China in the midst of Chairman Mao Zedong's crazily utopian Great Leap Forward, the official Communist Party newspaper issued some dietary instruction for the masses of the country's newly collectivized agricultural workers. ''The peasants must practice strict economy,'' The People's Daily intoned. ''Live with the utmost frugality and eat only two meals a day, one of which should be soft and liquid.''

Life and history are in the details, and one of the many virtues of this disturbing and important book by the British journalist Jasper Becker is its attention to the small, concrete matters that display larger, more abstract ones in the fullness of their horror and absurdity. ''Hungry Ghosts'' is Mr. Becker's powerful, sober, lucid and sometimes lurid account of what was probably the worst famine in history, the one that resulted from Mao's blindly misguided and ruthlessly enforced attempt to achieve Communism overnight.

For the party newspaper to tell people that it was good for them to eat less at a time when it was also spinning fantasies about the bounty being engendered by the Great Leap was a relatively small, if telling, irony. At the larger, horrific center of Mr. Becker's account is the widespread resort among the Chinese people to that most sickening form of desperation: cannibalism, the selling of human flesh on the market, the swapping of children so people could use them for food without committing the additional sin of eating their own.

It has of course been known for many years that the Great Leap produced a terrible calamity in China lasting from roughly 1959 to 1962. But Mr. Becker, who is the Beijing bureau chief of The South China Morning Post, has written the most compelling and complete account of that calamity, describing it systematically as it affected the countryside, the cities and the immense network of camps for ''rightists'' and other political prisoners that China maintained at the time.