Abstract: Some biological aspects of pond cultured postlarval Eriocheir sinensis were studied from June to November,1993. The survival of the experimental population was 18.6% as the crabs grew from 7.3 to 32.8 mm in mean carapace length. The relationships between body weight and carapace length or carapace width were described. Female crabs had the same growth rate as male crabs. The growth curve of carapace size or body weight was fitted well by a logistic equation. Sex ratio at each sampling time did not differ significantly from theoretic value of 1∶1(Chi square test,p0.10). Puberty molt of most females was observed in mid September,and the size of females at sexual maturity ranged from 26.2 to 49.8mm in carapace length,while the immature females were 26.0\41.2mm in carapace length.