Abstract: The variation in wood properties and the differences between juvenile wood and mature wood of Masson Pine(Pinus massoniana) plantation from Guangxi were studied. The results are as follows: The boundary between juvenile and mature wood was delimited at the age of 14～16 year. The radial variation patterns of the anatomical properties from pith to bark are: the ratio of ray tissues, ratio of resin canal, cell walls percentage, lumen diameter, wall thickness of tracheid, tracheid diameter, tracheid length, ratio of wall to lumen (latewood) increase with the increase of growth ring, while ratio of tracheid and ratio of lumen to diameter decrease with the increase of growth ring. Most parameters of the anatomical properties of mature wood are higher than that of the juvenile wood with significance level shown in ratio of resin canal, cell walls percentage, wall thickness of tracheid, tracheid diameter, tracheid length. All of the physical and mechanical properties of mature wood are higher than that of juvenile wood significantly. Analysis of relationship showed that the ratio of ray tissues, ratio of resin canal, rate of cell wall, tracheid length were positively correlated to wood density with significance level. The MOR, MOE, and crushing strength were positively correlated to wood density significantly in juvenile and mature wood.