Abstract: Genetic similarity,genetic distance and Shannon's genetic diversity of two different artificial gynogenetic grass carp groups and a control common grass carp group were analyzed in the methods of RAPD (Random Amplified Polymorphism DNA).One of the two different gynogenetic groups was a meiotic-mito-gynogenetic grass carp group that was produced by artificial gynogenesis for two generations. Another.gynogenetic group was a mito-gynogenetic grass carp that was generated by artificial gynogenesis only one generation.The common grass carp group was randomly collected from the markets in Changsha. Total 291 loci were detected in all of the three groups through the RAPD-PCR with 26 polymorphic random primers. The loci number in the three groups,meio- mito-gynogenetic group,the mito-gynogenetic group and the common grass carp group,were 265,272 and 282 and the number of polymorphic loci were 15,19 and 81 respectively. Genetic statistical analysis showed that percentage of polymorphic loci of the three groups of grass carp,were 5.66%,6.99%,28.23%;and the genetic similarity within the three groups of grass carp estimated by Nei’s index were 0.9851,0.9820,0.9114,respectively. The genetic diversity indices within the three groups of grass carp estimated by Shannon index of phenotypic diversity were 0.1722,0.3169 and 0.8450 respectively. Generally,the genetic diversity within two artificial gynogenetic groups of grass carp is far lower than that of common grass carp,while the genetic diversity in meiotic-mito-gynogenetic grass carp group is much lower than that of mito-gynogenetic grass carp group. The relatively low level of genetic diversity in each of the two groups of gynogenetic grass carp revealed that the population purity in each of the two gynogenetic grass carp groups is higher than that of common grass carp group.