Abstract: The apparatus and method of inoculating mosquitoes established by Rosen Gubler (1974) have been introduced to Shanghai by Dr. Gubler since October, 1984. Observations on inoculating microfilariae of Brugia malayi into four species of mosquitoes were carried out in our laboratory. Anopheles sinensis, An. lesteri anthropopha-gus, Aedes togoi and Culex pipiens pallens four to five days old were immobilized on wet ice. Each immobilized mosquito was placed on a slide under a binocular microscope. A needle was made by drawing out a glass capillary tube on the flame of an alcohol burner. The injection was made into the ventral surface of the neck membrane or the anepisternal cleft below the mesothoracic spiracle of the mosquito. B. malayi microfi lariae were taken from the peritoneal cavity of an infected mongolian jird. Inoculated mosquitoes were dissected every day or after an incubation period of 7-11 days at 27℃ in an insectary. Data showed that both An. sinensis and An. lesteri anthropo-phagus were susceptible to the inoculation of B. malayi microfilariae. The positive infective larva rates of Aw. sinensis and An. lesteri anthropophagus were 48.9% and 35.0% respectively. C. pipiens pollens was susceptible to B. malayi by inoculation too. Its positive infective larva rate to B. malayi was 51.6%. But the development of microfilariae in C. pipiens pollens was delayed for about two days than in An. sinensis. A less susceptibility to the inoculation of microfilariae of B. malayi was found in Ae. togoi.