Phosphorus (P) is an essential element for growth and development of plants. At cellular and sub-cellular levels, P plays a vital role in various important metabolic processes, such as protein synthesis, cell division, newborn tissues development and energy transformations. In terrestrial ecosystems, P is often the most limiting nutrient. This is particularly the case for some regions where nitrogen (N) in the soils is likely saturated due to high N deposition, extensive N fertilizer application and fossil fuel combustion. In this study, changes in P formations (total P, available P, inorganic P and organic P) in soils were investigated in three aged stands of Chinese fir plantations (7-, 17- and 25-year-old stands) in Huitong County, Hunan Province, China. The fractions of inorganic P in soils were also determined in the studied plantations. The purpose of this project is to examine the alterations of soil P in different aged Chinese fir forests. The results showed that the total P content ranged from 317.06 to 398.56 mg/kg and available P content from 0.82 to 1.38 mg/kg, in the three examined aged stands. The total P and available P contents were in a relative low level when compared with the corresponding values derived from the national soil survey. But the total P and available P contents in soils significantly increased with the aged stands. The average total P content in soils was about 19.68% and 15.75% higher in 17-year-old stands and 25-year-old stands than in 7-year-old stands. Available P content was about 45.55% higher in the 17- and 25-year-old stands than in the 7-year-old stands. P activation coefficient in the soils was low (< 2.0%) in the three aged stands of Chinese fir forests, which suggested that the transformation of organic P to available P was restricted, even certain mineralization indeed occurred in the studied site. The concentration of inorganic phosphorus was 169.50, 182.03 and 175.94 mg/kg in the 7-, 17- and 25-year-old stands, respectively. On average, the amount of inorganic P fractions in the studied soils was in an order: occluded bound P (O-P) > iron bound P (Fe-P) > calcium bound P (Ca-P) > aluminum bound P (Al-P). Significant changes in the patterns of absorption of inorganic phosphorus fraction occurred in different growth and developmental stages of Chinese fir forests. Typically, the Al-P fraction was the major component of the inorganic P absorbed by the tree in the 7- and 17-year-old plantations. But the Fe-P and Ca-P fractions became the most assimilated inorganic P in 25-year-old Chinese fir stands. It was found that there was a close relationship between the available P and organic P in soils with a correlation coefficient of 0.667 in the studied stands, which implied that the organic P was the main source of soil available P in Chinese fir plantations in the study region. The results suggested that it was likely an important management practice to increase the transform rate of inorganic P to available P in the younger stands in order to improve soil fertility and promote forest productivity. Our study provided a scientific basis and reference for better understanding of P storage and cycling in Chinese fir forests.