The four fishes,Silver Carp (Hypophthalmichthys molitrix),Bighead Carp (Aristichthys nobilis),Grass Carp (Ctenopharyngodon idella) and Black Carp (Mylopharyngodon piceus),are native to China and have been cultured.They have also been introduced to culture in many countries in geographic regions.Approximately the four species have successfully established wild populations in half of those countries.The invading rate is greatly higher than any other invasive species.The success of invasion is attributed to their high fecundities,broad physiological tolerances,variable feeding behaviors and population genetic diversity,as well as the environmental adaptability of new habitats.Any river long enough and with fluent water flow will provide essential environment for their survival and reproduction in the wild.The climatic factors are also significantly correlate with the successful invasion.Furthermore,the abundant food and compatibility with other invasive species also facilitate the four fishes to rapidly become invasive species if their population available in the introduced regions.