Abstract: Field control of malayan filariasis was carried out from 1964 to 1979 in Miaoxi Commune, Zhejiang Province. In the first stage from 1964 to 1967, the measures used were chemotherapy with DEC and residual spraying with DDT in human dwellings and animal sheds. Follow-up examination in 1968 showed thai the microfilaremia fate dropped from 20.21% to 0.7%, infective larvae were not found in mosquito vectors and the morbidity of filarial lymphangitis decreased gradually after control. When checked up 6 years later in 1974, it was found that the microfilaremia rate was 1.26%, 38.1% of the microfilarial positive cases were new immigrants, and some of the originally positive cases turned to be negative without treatment. These data indicated that the transmission of filariasis has been effectively controlled during this period. In the second stage (1974-1979), selective treatment with DEC was conducted. Thereafter the microfilarial rate was reduced from 1.26% to less than 0.2%. Since then, several blood surveys of the population in the commune showed that the microfilaremia rate was maintained at the low level throughout and no new infection among infants was found.