Patterns of variation in the chemical composition of wood,i.e.,holocellulose,cellulose and lignin contents and 1%NaOH extractives were studied in 12 natural populations of Pinus manssoniana Lamb.in Guizhou Province,China,using wood cores as experiment material.The results show statistically significant differences among provenances in holocellulose,cellulose and 1% NaOH extractive contents.The largest coefficient of variation among the provenances was found in the 1%NaOH extractive content and the smallest in the holocellulose content.Variation of lignin content occurred within provenances.Correlations between chemical compositions of wood and factors of local geography and meteorology were largely insignificant.The chemical composition of wood presented patterns of random variation.The correlation of 1%NaOH extractive content with holocellulose content was significant(r=?0.68).There was also significantly negative correlation(r=0.62)between cellulose and lignin content.On the basis of a UPGMA cluster analysis,we identified three provenances of masson pine among the 12 studied,i.e.,those of Wengan,Tongzi and Luodian with high cellulose contents,low levels of 1%NaOH extractive and moderate lignin contents,which we recommend as promising provenances for growing of pulp wood and the manufacture of paper in Guizhou Province Patterns of variation in the chemical composition of wood, ie, holocellulose, cellulose and lignin contents and 1% NaOH extractives were studied in 12 natural populations of Pinus manssoniana Lamb. In Guizhou Province, China, using wood cores as experiment material. The results show statistically significant differences among provenances in holocellulose, cellulose and 1% NaOH extractive contents. largest coefficient of variation among provenances was found in the 1% NaOH extractive content and the smallest in the holocellulose content. Variation of lignin content occurred within provenances. Correlations between chemical compositions of wood and factors of local geography and meteorology were largely insignificant. The chemical composition of wood presented patterns of random variation. The correlation of 1% NaOH extractive content with holocellulose content was significant (r =? 0.68) .There was also significantly negative correlation (r = 0.62) between cellulose and lignin content. On the basis of a UPGMA cluster analysis, we identified three provenances of masson pine among the 12 studied, ie, those of Wengan, Tongzi and Luodian with high cellulose contents, low levels of 1% NaOH extractive and moderate lignin contents, which we recommend as promising provenances for growing of pulp wood and the manufacture of paper in Guizhou Province