Abstract: According to related studies, mean daily temperatures of 5.87℃ and 15.17℃, and effective accumulated temperatures of 3846.28 d·℃ and 842.95 d·℃ were taken in this paper as the low limit temperature index and effective accumulated temperature index for growth of Oncomelania (snail) and Schistosome, respectively. Considering 1986 a division and using daily mean temperature data during 1950-2003, the changes of start and end days when five-day moving average temperature steadily passed 5.87 ℃ and 15.17℃ under the 80 percent guaranty rate, and the effective accumulated temperatures for the growth of Oncomelania and Schistosome were computed year by year for each of 220 meteorological stations in the region of 18°-41°N, 99°-124°E, respectively. The variations of their growing period and effective accumulated temperature before and after 1986 were analyzed by means of ArcGIS8.3. The results suggest that the climate change in 1950-2003 has possibly increased the density of snail and prolonged the schistosomiasis infection period.

Key words: climate change, Oncomelania, Schistosome