Abstract: In November 2003 and June 2004the boring insects and their spatial distribution within Pinus massoniana forest were investigated in Zhoushan CityEast China's Zhejiang Province where Bursaphelenchus xylophilus happened typically.And thenthe niche widthproportional similarity of niche and the niche overlap of dominant species of dying trees were computed.Results showed that 5insect species infected and damaged Pinus massoniana which had been infected by Bursaphelenchus xylophilus.Among which four were wood boring beetles and one was termite.Species within host trees varied from winter to summerand all of the species had their own niche widthproportional similarity of niche and niche overlap.So they can achieve competitive equilibrium and coexistence according to their biological characteristics and life habits.