Abstract: Impacts of adult feeding materials on female reproduction capacity of the Japanese sawyer,Monochamus alternatus Hope,major vector of the Pine Wilt Disease,were investigated through rearing experiments in 2000-2001 in Xiangshan,Zhejiang Province.The Results showe that there is a comprehensive impact on adult female reproduction capacity of the sawyer.Indexes related with female reproduction,such as pre oviposition period,female life span,eggs laid in 24 h,and rate of egg hatchment,are all got affected,of which the life span of adult female and eggs in 24 h are the most important affected indexes.When fed with current grown Pinus masoniana branches,all the above mentioned indexes get decreased compared with those fed with mixed branches,and decreases with the age of branches in general.The result of the comprehensive impact is that the average number of progeny per female decreases with the age of feeding branches,82.07 with mixed branches,76.62 with current grown branch,8.82 with two year branch,and 0.16 with three year branch respectively.