from Yellow River, Taihu Lake, Taiwan and Japan were used to optimize PCR amplification conditions to develop DNA fingerprinting technology by RAPD primers. The results showed 20 RAPD primers could amplify PCR products in four different poplations under the optimization conditions. The result also demonstrated that PCR products amplified by RAPD primer S105 in population Yellow iver were different from those in other three populations, while RAPD primers S327 and S474 could differeniate Japan and Taiwan populations from other three populations, respectively. Therefore, the optimization of annealling temperature and cycles numbers is beneficial to the development of RAPD technique of . Meanwhile, the reasonablity and its affecting factors of RAPD technique was also briefly discussed in this paper, which can provide the interest information for similar researches