Objective To describe the invasion of exotic species into the composition of fly fauna in China and the significance of human-induced invasion of fly vectors. Methods The disaggregated data on Muscidae, Calliphoridae and Sarcophagidae in China were analyzed. Results Among all the fly vectors of Fanniidae, Muscidae, Calliphoridae and Sarcophagidae in China, 78 species were distributed in the China-North America, China-Africa, China-Australia, China-Europe-South America, China-Australia-Africa, China-North America-South America, China-Europe-Australia and China-Africa-America ecozones as well as the worldwide ecozone, accounting for about 5.0% of all known species in China. A total of 84 species of 4 families were distributed in China-Europe-North America, accounting for 5.3% of the known species. Those distributed in China-Europe, China-Asia-Australia and China-Europe-Africa amounted up to 233 species, accounting for 15.0% of all known species. The larvae of these cosmopolitan species were either coprophilous or saprophytic, and most of the adult flies lived in the same living environment as human beings or domestic animals. Of the 35 major polluting fly species living in residential or semi-residential areas settlements in China, 22 showed disjunctive or global distributions in the worldwide ecozone, and the other 4 were widely distributed in the Palaearctic, Oriental and Australia regions. Conclusion Many a species of the fly vectors in China was introduced from abroad through human activities. Human activities constituted a leading cause for the invasion of flies.

A total of 57 species, 34 genera of Sarcophagidae in Guangdong and Hainan were identified, including 44 species in Guangdong and 25 in Hainan. Robineauella walayari (Senior-White) was a newly recorded species in China, in addition to other thirteen newly recorded species from Guangdong and two from Hainan. Sinonipponia hainanensis (Ho) was first recorded in Hong Kong. The flesh flies in Guangdong and Hainan were mostly of the subfamily Sarcophagidae.