Abstract: In order to promote soil nutrient evaluation and sustainable development of Pinus massoniana plantation, the soil aggregates of Pinus massoniana plantation in different age groups（middle-aged forest, near-mature forest, mature and over-mature forest） in Karst Area of southwest China were studied.The changes of soil aggregate carbon, nitrogen and phosphorus storage in 0-20 cm soil layer were analyzed, and their relationship with soil carbon, nitrogen and phosphorus storage were discussed.The results showed that among different age groups, the variation trend of soil carbon, nitrogen and phosphorus storage in Pinus massoniana plantation was near-mature forest ＞ mature and over-mature forest ＞ middle-aged forest, and forest age had a significant effect on soil carbon and nitrogen storage.With the increase of forest age, the nitrogen storage of clay silt increased gradually, and the nitrogen storage of mature and over-mature forest in clay silt increased significantly by 43.40% compared with that of middle-aged forest.The phosphorus storage of soil macroaggregates increased first and then decreased with the increase of forest age, and the phosphorus storage of near-mature forest was significantly higher than that of mature and over-mature forest by 18.21%. There was a significant positive correlation between soil total nitrogen storage and total nitrogen storage of macroaggregates, soil total phosphorus storage and total phosphorus storage of macroaggregates, microaggregates and clay silt. It is concluded that forest age has a significant effect on the total nitrogen storage of soil clay silt and the total phosphorus storage of macroaggregates in Pinus massoniana plantation, while the phosphorus storage of macroaggregates is greatly affected by soil phosphorus storage. Phosphorus fertilizer can be appropriately applied to the management of Pinus massoniana plantation and attention should be paid to the management and protection of near-mature forest.