Schistosomiasis is known to be endemic in the lake Lindu area since 1937 (Brug & Tesch, 1937). Investigations carried out later between 1940 and 1942 (Bone et al., 1942) failed to find molluscan intermediate host. It was not until April 1971 that the first specimen of Oncomelania was found (Carney et al., 1972). In August of the same year the first focus was discovered at Paku (Hadidjaja et al., 1974). Further investigations revealed 50 more foci in the lowlands surrounding the lake. A survey of the habitat in the Napu Valley revealed 15 more Oncomelania colonies (Crney et al., in prep.). The morphology studied by Davis and Carney (1973) showed that this snail has a close resemblence to O. h. chiui and O. h. quadrasi. It was given the subspecies name Oncomelania hupensis lindoensis. Snail cultures maintained according to Davis' method (1971) were done in the laboratory of the Department of Parasitology, Faculty of Medicine, University of Indonesia. Diatoms and algae were given as food. Biology of the snails concerning the temperature, hymidity, mortality rate of the snail or survival rate and also the living and egg laying habits of the snails were described.