Postembryonic development and growth of laboratory cultured rare minnow, Gobiocypris rarus were studied from 1990 to 1993. The postembryonic development is divided into early-stage larva, late-stage larva and juvenile period on the basis of the external morphology, internal morphogenesis and biological characters. A total of 11 stages are subdivided among the dme periods. At the water temperature ranging from 24.7 to 31.8degreeC, the postembryonic development lasts 25 to 30 days, and the larva grows uniformly with a growth rate 0.52 mm per day. Cultural conditions influence the development and growth effectively. In similar conditions, descendants from different populations grow at the same growth rate no matter whether their parents were captured in Hanyuan County, Guanxian County, or Penxian County.