Abstract: 4 years'test data study on 17-year-old near-mature Masson Pine fertilization showed that applying N fertilizer was disadvantageous to the growth of plantation in short time in south red soil area,while fertilizing properly P and K improved the growth of near-mature plantation significantly and applying much was disadvantageous.It would cover up site affections on growth of tree when affecting is significant after fertilizing.Accord to the analysis of effects of different treatments,it showed that optimal application amounts of P,K were P₂O₅ 90g,K₂O 90g per tree,compared with the control,which increased the periodic increments of volume by 13.4% after 4 years.Fertilization could promote smaller diameter grade tree growing.Regression analysis showed that fertilization presented significant correlation to growth of near-mature forest.

Key words: near-mature Masson Pine plantation, fertilization, growth effect, analysis of variance