Abstract: Schlechtendalia chinensis (Bell) is the most important gall-aphid made of Chinese gall-nuts in the world. The output of Chinese gall-nut caused by Sehleehtendalia chinensis (Bell) is directly related to the number of the insect migrating from the secondary hosts or overwintering hosts, mosses belong to the genus Mnium Hedw, to the primary host (Rhus chinensis Mill) on which the galls are formed, but the patterns of the migration of the spring migrants is not yet known. Therefore, during these two spring seasons in 1984 and 1985 some observations were made and the results are as follows:1. The migration period takes 23—32 days, but 70—80 per cent of the migrants fly out of the overw,intering hosts within discontinuous 3—5 days. The peak of migration is only once oneday, with its appearance at13—16 o'clock.2. For the most part of the migrants fly from overwintering hosts in sunny days with higher temperature, a few in cloudy days, none in raining days.3. Temperature is the most important climatic condition for migration which does not oecure below 10℃ with the optimum temperatureover 15℃.4. The migrants are not active if the mosses are wetted. The optimum humidity is below 80%. It is not favorable for the migration when the humidity is over 85%.5. Sunlight and lamplight from one to forty thousands Lx may cause its flying with the direction towards the stronger illumination.