Based on the correlation analysis between meteorological factors and each stage of Loxostege sticticalis Linnaeus, we surely confirmed the key stage , key factors and its terms, which could take influence on the first generation larva. The first generation larva could not be appeared unless two prerequisite condition be matched: 1. Enough overwintering adult of Loxostege sticticalis Linnaeus, 2. Meteorological factors during hatching eclosion stage are benefit to overwintering adult. Based on the first condition, the key stage is 10 days after the trapping peak of overwintering adult, and the key factors is temperature. During this stage ,the lower mean temperature(<18℃)or mean min-temperature(<13℃)will suspend oviposition apparently，which could against the first generation larva. On the other hand，the mean temperature between 22 and 24℃ are good at the first generation larva. In this paper ,the result could be used as a reference for Loxostege sticticalis Linnaeus control.