Abstract: The overwintering survival rate of the mature yearling Chinese mitten-handed crab, Eriocheir sinensis, was 11%. The survinal curve can be expressed as Y=1.09exp (-0.018x)(Y:survival rate, x:days) from Dec. to Jul. During cultivation period in a small basin (3.3 hm2) of Bac’ An lake, the drily feeding rate of mature crabs was not higher than 1.2% when fed on fish meat. The mature crabs did not cast off their crusts, and the last one died in the middle of July. On the basis of samples of mature crabs in Biandan-tang lake and the small bay, and obersavations of the crabs' behavior and the survival rate of the mature crabs, it is proposed that the mature yearling crabs may not be suitable for aquaculture in macrophytic lakes. But the precocious crabs can be harvested before April each year.