Abstract: Phloeosinus sinensis Schedle is an important insect pest which bores the stem bark of the Chinese fir (Cunninghamia lanceolata). It has one generation a year in Zhejiang and Anhui Provinces and lives through winter in adult stage. Its aggregating and dispersing cycle, the boring habit of the adults and the larvae, and the environmental factors for this bark beetle's occurrence have been studied. Chemical control of using 80% DDVP or 75% phoxim emulsions to kill the aggregated adults under bark and using wood-baits to attract the adults then to spray them with chemicals have been suggested as control measures.