Abstract: Population dynamics ofmajor Coleop tera insects in mature and immature p ine forest distributed under thealtitude of 100 m in northern p iedmont of Kuocang Mountain were investigated by using trap s and attractant in2005—2006. Results showed that there were 33 Coleop tera species, belonging to 9 families, damaging massonp ine, either p ine needles or branches and trunk, and 1 natural enemy species. Of the insect pests, 3 were victors ofthe fatal p ine disease PWN, i. e. M onocham us alterna tus, Spondy lis buprestoides, and S hirahoshizo patruelis. In thetrial forest compartments, Cerabycida, Curculionidae and Scolytidea were the dominant group s with both speciesnumber and total insect individuals attracted. Important adult characteristics of major species, esp. M onocham usalternatus were analyzed and suggestions on p revention and control of these major species were given.