Abstract: In this paper we selected 20 Chinese pine standard sample plots and,according to the principle of the polygon sample plot layout,set up 100 polygon sample plots.The measuring factors include the average height,DBH,mean density and forest stock volumes.comparing with the data of standard plots we can get the accuracy of the polygon plots.The results show that the accuracy of polygon plot method in artificial forests is higher than that in natural forests.The accuracy of forest stock volume can reach 92.8% in artificial forests and 89.2% in natural forests.

Key words: polygon plot method, forest resources survey, precision