Abstract: In order to research the relation Pilodyn penetration and wood properties,the living tree of Pinus armandii was penetrated by Pilodyn in both south and north directions in the field. The wood basic density and fiber length and width of increment core were measured in door. Through the analysis of Pilodyn penetration, the basic density of increment core, fiber length and width, the results showed that the Pilodyn penetration of Pinus armandii had no significant differences in the north and south directions. The result was the same as outer wood density and basic density and with outer wood density. Pilodyn penetration had highly significant correlation with basic density. The biggest contribution rate to the multiple regression equation was wood density (52.86%--63.74% ). The model using the average of Pilodyn to estimate wood basic density was made through a linear regression metted. The Pilodyn penetration could estimate the average of outer wood density in an entire radial direction in living tree of Pinus armandii. It could also estimate the basic density in an entire radial direction.