Abstract: The effectiveness of "hunmiewei" and deltamethrin against A. sinensis was evaluated by means of susceptibility test, experimental huts and field trial during 1983-1984 in Tangtou of Shinan. The results showed that both insecticides were highly toxic to A. sinensis which had developed high resistance to organochlorine and organophosphorus insecticides. The residual effect on bamboo walls in the experimental huts was three months or more for deltamethrin at 25mg/m2 and 45-50 days for "hunmiewei" at 2g/m2. In a field trial, house spraying of deltamethrin and "hunmiewep at the above mentioned dose, two rounds in a year, could reduce vector capacity of A. sinensis by 91.4% and 85.2% respectively as compared with that in control village; when insecticides were used in combination with adequate chemotherapy including anti-relapse treatment, case radical treatment and presumptive treatment in the sprayed areas, the morbidity rates of vivax malaria were decreased by 43.0% and 42.2% respectively as compared with those of last year.