44 p lotswere set up in different slash p ine p lantations in J iangxi Province. The relationship between themean population density of Hylobitelus x iaoi and the mean worm hole in slash p ine were investigated and 5 functionswere found respectively. The results showed that the best suitable mathematics model could be described as: Y =0. 082x2 + 0. 2 216x + 0. 063, and the table of relationship between the mean population density of H. xiaoi and themean worm hole in slash p ine were established, which p rovided a simp ly method for number investigation andforecast of H. x iao in slash p ine p lantations.