Abstract: The critical values of potential soil nutrients in Pinus kesiya var. langbianensis plantations were caculated according to the relations between the potential soil nutrients and the stocking volume through standard plots investigation in Jinggu, Yunnan province. By adopting K-Means Cluster Analysis methodolgy, the plantation soil was classified into 4 types on the basis of farmating the values of the potential soil nutrients and the stocking volume, then the critical values of potential nutrients for different soil types were calculated. The results showed that the critical values of potential soil nutrients for P. kesiya var. langbianensis plantations in Jinggu were0.640 0,0.895 0(g/kg) for total N; 0.307 8,0.431 1(g/kg) for total P;and3.327 3,4.004 6(g/kg) for total K.