描述了长江、瓯江、辽河水系河蟹 ( Eriocheir sinensis)种群的主要生态和形态特征。三个水系的河蟹在生态、形态、几种同工酶及遗传多样性上存在差异 ,但差异不大 ,尚不足以形成特征群体。据此认为三个水系的河蟹是属于同一个种的不同种群。同一水系蟹种的质量应从外形、个体规格、均匀度、伤残率、复位能力、肥满度和致病菌、寄生虫的感染寄生等指标上加以鉴别。 The main ecological and morphological characteristics of Eriocheir sinensis populations in the Yangtze, Oujiang and Liaohe rivers were described. The crabs in the three water systems differed in their ecology, morphology, isoenzymes and genetic diversity, but the difference was not significant and not enough to form the characteristic population. Accordingly, the three river crabs are considered to belong to the same species of different populations. The quality of the same water crab species should be identified from the appearance, individual size, uniformity, disability, reset ability, fatness and pathogenic bacteria, parasite infection parasitic indicators.