Abstract: Trichagalma glabrosa is an important pest of cork oak. In recent years，outbreaks of Trichagalma glabrosa have caused great damages to cork oak forests and ecological environment in Liuzhou (Henan Province). In order to study dynamic population of Trichagalma glabrosa, the life table of Trichagalma glabrosa population was constructed. The results showed that: gall abortion was the key factor affecting the natural populations, and the initial period of galls was the key death stage. The order of death factors was: parasitism＞gall abortion＞leaf-eating insect feeding＞unknown factor. The order of development stages was: galls mature stage＞galls growing＞galls initial stage＞pupal stage. This indicated that Climatic changes during galls initial stage was the key factor affecting population, parasitism was the most important control factor. The population trend index I was 2.34＞1, and the population showed an increasing trend.