Phenotypic plasticity (the ability of an organism to change its phenotype in response to changes in the environment) is considered to be one of the important mechanisms to found the biodiversity in resent. It is clear and convincing that the speciation induces the biodiversity and if the organisms diversify by the phenotypic plasticity, we can consider that the phenotypic plasticity can be trigger for the speciation. Myrmecina nipponica is ant species contains two types of colonies: winged and wingless queen colony in sympatric field. A culture experiment shows this two queen phenotypes are the plastic phenotype, but on the field, winged queen colony produce winged queen and wingless queen colony produce wingless queen for next generation. In this situation, an important question is the gene-flow between winged and wingless colony by male. Dose the male from winged colony and wingless colony prefer to mate to winged queen and wingless queen? Or they mate to both queen randomly? If we find the bias of genetic frequency, it is considered to be on the way to genetic division will be speciation induced by phenotypic plasticity. Using the microsatellite analysis, we will discuss the bias of gene flow between both types of colonies to clarify this hypothesis.