Mosquito fish（Gambusia spp.) were native to North America and had been regarded as evil invasion species. For the great predation pressure on mosquito larvae，they were introduced into temperate and tropic area to control mosquito population in wild since early 20th centuries. The intensive investigations indicated that mosquito fish invasion had great threat on the survival of native invertebrate, fish and amphibian in field through predation and competition, thus having great risk on native aquatic ecosystem. Mosquito fish had large habitat niches, rapid growth rate, ovoviviparity, high reproduction rate and large adaptation reproduction conditions. In wild, their population sizes increased rapidly, and the individual span were no more than 2 years. In reproduction season, the population formed spring and summer reproduction groups, and they had different reproduction strategy, resulting in complex population structure. In addition, the female had the ability to store sperms from different males for a long time and use these sperms to release several broods in a reproduction season. Such broods had relative high inheritance diversity. By this way, the introduced population could easily to pass through bottle neck to exhibit rapid evolution and form different geo-population. For the sake of mosquito control, mosquito fish dispersal will be continued in the future, and the ecological invasion risk of such fish needs further study.