Abstract: In order to specify the population dynamics of Leguminivora glycinivorella in Mudanjiang and its relationship with meteorological factors, the test used sex attractant trapping method in field during 2010- 2012. The results showed that Leguminivora glycinivorella started in late July and reached the peak in early August to mid-August, ended at the end of August, lasting for 30 days. Population dynamics of Leguminivora glycinivorella was significantly positive related to the average temperature in years with less rainfall. Moderate rainfall could cause high air humidity, which led to increasing amount of moth, but heavy rainfall was unfavorable for Leguminivora glycinivorella pupation and adult unearthed. In Mudanjiang, daily average temperature at 21- 24℃was optimum for the occurrence of Leguminivora glycinivorella, and constant high temperature and drought weather was not conducive to adult occurrence. Therefore, temperature and precipitation were important factors affecting the occurrence of Leguminivora glycinivorella.