Abstract: Sitodiplosis mesollana (Gehin) have 4 forms in the soil.They the distributed most in the middle layer (7-13cm)，less in the lower layer (13-20cm)，the and least in the upper layer (0-7cm),They are also found in the layer ranging from 20-38cm, Their larvas are most in the upper layer less in the middle layer，and least in the lower layer, Round found the most in the middle and lower layers，the、least in the upper layer.As for long cocoons and pupas，they are found the most in the upper layer，and less in the middle and lower layers, The critical factor for the time and duration of adults occurrence is the rainfall in March, April and May，and the rainfall in April is the most important, The rainfall in late April is heavy，so adults occur early and last a long time, and the peak of adult occurrence coincides with the pcroid of wheat ear sprouting，wheat will be heavily damaged.Before the ear sprouting application of slow-release insecticide to cover the ground surface can kill the larvas and pupas which increasingly rise to the surface，and prevent adults from emergence.

Key words: Wheat, Sitodiplosis mosellana (Gehin), Pattern of occur-rence.Shanxi province