Abstract: Based on the theory of fishery resources assessment and the characteristics of fishery stock enhancement and releasing, the method was put forward to assess the enhancement effect of fishery stock by calculating the biological statistics amount of population. The growth parameters and natural mortality coefficients of the enhancement species that hadn't been built the growth equations were estimated and the suitable enhancement amounts of all enhancement species were estimated by choosing the suitable model of fishery stock assessment. The method to confirm the recapture amount from the enhancement seedlings of the total catch was pointed out. The formulas to estimate the fishing mortality coefficient, and the surplus amount, the recapture amount, the recapture rate as well as the recapture benefit from the enhancement population by the time series were developed.