[Objective] The distribution characteristics of inorganic phosphorus in the soil profile during the ecological restoration process in the karst plateau canyon of Guizhou Province were studied, in order to provide a scientific basis for the research and scientific management of soil phosphorus in the ecological restoration process in karst mountain.[Methods] Four types of representative plots (cultivated land, converted cropland to grassland, barren grassland, and forest-grass intercropping land) were selected in Liancheng Town, Qinglong County, Guizhou Province, to study the morphological characteristics and influencing factors of soil inorganic phosphorus.[Results] The contents of total phosphorus and available phosphorus in four representative plots were 1.96~3.88 g/kg and 1.16~11.25 mg/kg, respectively. The total amount of inorganic phosphorus ranged from 591.39 to 1024.79 mg/kg, which was manifested as cultivated land > returning cultivated land to grassland > forest-grass intercropping land > wild grassland. Phosphorus activation coefficient (PAC) in different soil profiles was much less than 2%. The content of inorganic phosphorus in different forms was showed as follows:OP > Fe-P > Ca-P > Al-P. All forms of inorganic phosphorus showed a very significant positive correlation with fast-acting phosphorus (except OP). Inorganic phosphorus in different forms was positively correlated with available phosphorus. Different forms of calcium (water-soluble calcium and exchangeable calcium), as well as pH value and clay content, affected the proportion and conversion of inorganic phosphorus.[Conclusion] In the process of ecological restoration, the research area gradually recovered from cultivated land to grassland, to wild grassland, and to forest and grass intercropping. The soil physical and chemical properties were improved, and the soil phosphorus content was increased.