Pissodes punctatus Langor et Zhang is widely distributed in Yunnan, and the area of damaged Pinus armandii forest is about 6 670 hm² in Haizhai state-owned forest farms in Qujing. Through the six_year research of the natural population dynamics, the development process of the beetles was divided into five stages, i.e. egg stage, first larval stage, second larval stage, pupa stage and adult stage. Through the field observation and rearing in laboratory, life table of natural population was constructed. Through regression analysis, the main key factor of population dynamics was Beauveria bassiana in second larval and pupa stage, and the second key factors was the parasitic wasps.