Abstract: Human filariasis in China prevails in 864 counties and cities covering 14 provinces, municipalities and autonomous regions (Taiwan Province not included), among which 467 (54.1%) were endemic to filariasis bancrofti, 225 (26.0%) to filariasis malayi, 138 (16.0%) to both types and 34 (3.9%) unidentified.The endemicity of filariasis in these counties and cities could be stratified into several strata based on the positive microfilariae rates before control: 419 counties and cities (48.5%) having infection rate below 5%, 318(36.8%) having 5.1-20.0%, 56(6.5%) having 20.1-30.0%, 11 (1.3%) over 30%, and 60 (6.9%) were unknown.It was estimated that prior to control there were about 30,994,000 filariasis patients, among them 21,962,000 suffered from filariasis bancrofti.The National Filariasis Control Program was initiated in 1956. The three therapeutic measures with DEC were: 1. selective treatment (microfilaraemia cases), 2. selective treatment and mass administration (all inhabitants above 5 years of age), 3. selective treatment and medicated table salt (9 grams of DEC within 6 months in areas endemic to bancroftian filariasis).In 1980, 21,313,000 filariasis patients (microfilaraemia positive and symptomatic) were found negatively conversed or cured. The filarial infection rate was likewise greatly reduced. Among the 864 endemic counties and cities the infection rate of 708 (81.9%) were below 5%, and filariasis in 265(30.7%) were virtually eradicated (The positive rate of microfilaraemia in a production brigade taken as the unit of count was reduced to below 1%).The fact that there are still about 9,681,000 filariasis cases to be treated calls for continuous and even greater effort on our part to put the disease under control in our country.