They will say that homosexuality is part of "normal" sexual behaviour, with the proviso that those who are unhappy with their sexual orientation may still be judged to be in need of psychiatric help.
Wan Yanhai, who writes for a gay-oriented website, said the decision was "an important step for restoring the esteem of Chinese homosexuals".
The announcement follows a sometimes heated debate among Chinese psychiatrists. The traditionalists argued that homosexuality undermined family values, caused mental disorders and spread sexually transmitted diseases.
Those urging reform pointed to the existence of a gay minority in all societies and the change in China's social values .
Homosexuality has been frowned on since the 1912 nationalist revolution, when it was seen as part of the decadent imperial lifestyle. Al though not criminalised under communist rule after 1949, it became regarded as socially deviant. During the cultural revolution (1966-76) gay activity could lead to execution.
More recently gays remained liable to imprisonment without trial in re-education camps. If sent to psychiatric hospitals they were likely to receive electric shock treatment or aversion therapy.
The change in attitude reflects a more general shift in Chinese society - at least in urban culture - towards a greater tolerance of different kinds of sexual behaviour.