This paper reports on the studies of the role of Anopheles anthropophagus and Anopheles sinensis in malaria transmission in a sense to elucidate which one of the two species the predominance in this respect. Systematic investigations including artificial infection of mosquitoes, quantitative entomological studies and parasitological research were conducted in 1982-1987 in 5 pilot areas in Anhui (1), Guangxi (2), Sichuan (1) and Guangdong (1). The results revealed that the susceptibility of An. anthropophagus to Plasmodium falciparum was significantly higher than that of An. sifefsis. The oocyst rate and sporozoite rate of the former were 27.9% and 10.9%, while those of the latter being 11.3% and 3.0%. Significant difference in natural infection rate of the two species was also observed. The mean sporozoite rate of An. anthropophagus was 0.58% (105/17984), and that of An. sinensis was 0.02% (4/17718). Taking several essential parameters (man-biting rate, human blood index, vectorial capacity and entomological inoculation rate) into consideration, the role of An. anthropophagus in malaria transmission was 20 times more vigorous than that of An. sinensis. The malaria incidence and parasite rate of the inhabitants in site were closely related to the proportion of An. anthropophagus in human dwellings. According to the survey pursued in 1983; An. anthropophagus was the major vector playing an important role in the outbreak of vivax malaria in Shenzhen. The preceding results disclosed the important role of Anopheles anthropophagus in the transmission of falciparum and vivax malaria. The findings are of significance in the stratification of malaria endemic areas of the country and the analysis of current situation and programming malaria control measures as well.