The estimation of fish populations in certain waters is the basis of fishery resources management and conservation. The populations of Chinese sturgeon (Acipenser sinensis Gray) in the Yangtze River and its variation have received public attention and become a pending tough issue. Firstly, according to the features of reproduction population, the theory and method for estimating the populations of Chinese sturgeon in the Yangtze River from the year of 1981 to 1990 are established by using existing fishing data. It is indicated that between 1981 and 1990 there are 1,348 individuals on average with annual stock recruitment of 767 individuals in the Yangtze River. In addition, the estimation of Chinese sturgeon population and effects of fishing data are discussed, it is concluded that, (1) the theory and method for population estimation are feasible and of credibly accurate; (2) sensitivity analysis on the population estimation has been conducted; and (3) the level of resources utilization(fishing) has an obvious impact on both annual growth rate and immature individual scale factor for Chinese sturgeon.