Anopheles minimus was once a main malaria vector in Hainan Island and had been e-liminated basically through the campaign of indoor residual spraying launched in 1959. It again became an incriminated vector of some focal malaria outbreaks in recent years. The present study was conducted in a selected county-Danxian and a typical hilly area-Feibar in the west part of Danxian county in 1989-1990.An. minimus was found in 50% and 62. 5 % of the surveyed sites at mountainous and hilly area of Danxian county,but not found in coastal region. An. minimus was found in all 18 sites surveyed in Feibar district constituting 52% of anopheline composition. Man-biting rate made by human-baited collection was 3. 2 before midniaght and 38. 2 when collected through whole night in some sites. However, the behaviour characteristics of An. minimus has changed. It has become exophilic,exophagic, and has an equal preference for man and cattle. The vectorial capacity of An. minimus estimated by quantitative data was in accord with malaria infection rate in Feibar district ,and the malaria infection rate among the inhabitants in three types of residential quarter with different socioeconomic conditions. Malaria infection rates of residential quarter of land-reclamation outcomers, villagers and state farm residents were 10%,2. 9% and 0. 5% respectively during 40 days from July to August,1990.Owing to the fact that An. minimus has become a secondary vector only next to An. dirus, with a wide range of distribution and a considerable different characteristics in behaviour compared to that before spraying campaign , it is suggested that a malaria control programme must be seriously planned to adjust the new problem of malaria epidemiology in Hainan Province.