Abstract  [Objectives]  To investigate the population dynamics of the soybean pod borer (SPB) Leguminivora glycinivorella after diapause termination. [Methods]  Diapause (4 ℃, RH80%, L∶D=0∶24) and diapause termination [(26±1) ℃, RH80%, L∶D=16∶8] conditions were simulated in a laboratory and the effects of different diapause durations on the survival, pupation, eclosion and parasitism rate, were investigated. [Results]  Different diapause durations had no significant effect on the diapause intensity of SPBs; the average duration of diapause termination was 82 d. However, the longer the diapause duration, the less active SPBs became; 168 to 224 d of diapause was the duration required to produce a rapid decline in activity. Diapausing for this length of time caused the pupation rate to decrease from 21.9% to 1.9%, and the median survival time to decrease from 77 d to 35 d. The average emergence time of SPBs was 89 d compared to 60 d for their parasites, which indicates a degree of synchronization in diapause termination between parasites and host. [Conclusion]  At lower temperatures, SPB larvae can remain in diapause for a long time but under more suitable conditions larvae will develop and pupate after a shorter diapause period. These findings are helpful for predicting the frequency of occurrence of the SPB.