From July to August 1987, a quantitative study on the vector potential of An. kunmingensis (sp. nov.) in comparison with An. sinensis was carried out in nine malaria endemic villages of Tengchong County of western Yunnan. All the villages contained only three anopheles species: An. kunmingensis, An. sinensis and An. maculatus, among which An. kunmingensis accounted for 77% of 14,871 anopheline mosquitoes collected inside the houses and cowsheds. Adult density, man-biting rate, human blood index, sporozoite rate, parity rate and sporogonic cycle of all the three species were determined. The vector capacity appraised by using the above-mentioned indices of An. kunmingensis was far in excess to that of An. sinensis, An. kunmingensis was thus incriminated as the main malaria vector based upon its indoor abundance, relatively high man-biting rate and the finding of a sporozoite-positive specimen during the peak malaria season. In the light of its endophilic characteristics, residual insecticide has been used effectively in the control of An. kunmingensis.