To observe the host preference of Anopheles sinensis captured by outdoor human or cattle baits.A large number of non-blood-fed An. sinensis females were collected by overnight trapping outdoor with human and cattle in the rice paddy field in Shan County of Shandong Province, and took back to the lab, and individually labeled as human baits group and cattle baits group, fed with mouse blood. The host preference of parent, F1 and F25 generations of the two groups were observed by mark-release-recapture methods in a large greenhouse.The recapture rates of parent, F1 and F25 generations were 39.02% (1332/3414), 37.97% (2583/6803), and 30.55% (1523/4986), respectively. In parent generation, the proportion of mosquitoes from human baits group and cattle baits group collected by human-bait and cattle-bait was 54.07% (339/627) and 58.01% (409/705), respectively (χ2=19.42, P0.05).After culture for 25 generations in an experimental condition, the host preference for human or cattle of An. sinensis maybe change.