Phosphorus (P) is often the critical limiting nutrient controlling the productivity of wetlands. However, water eutrophication caused by P over enrichment impairs water quality and destroys wetland ecosystem. Very limited information is available on the characteristics change of P pool in wetland soils after returning farmland to lake (RFL). We used P fractionation techniques to investigate P distribution in soils, sampled from wetlands with various age (2, 5, 8, 10 and 20a) of RFL, rape field, and native wetlands in the Caizi lake, Anhui province. The results showed that the contents of inorganic P (IP) were in the order: Fe-P (73.55-391.76 mg/kg) > Ca-P (21.64-108.04 mg/kg) > O-P (17.15-29.57 mg/kg) > Al-P (5.84-25.97 mg/kg), moreover Fe-P, as a main component, accounted for 54.20%-74.13% of IP in studied field. All of Al-P, Fe-P and O-P declined within the restoration period of 2-8a, and began to increase gradually after 8a of RFL. The contents of Ca-P increased progressively with the age of RFL, and showed more and more contribution to IP. Soil inorganic P accounted for 35.90%-67.27% of soil total P, owning the same change tendency as Fe-P with various age of RFL, and dominated the change tendency of TP after RFL. Soil organic P accounted for 17.82%-50.51% of total P and increased gradually with the RFL age. With restoration age, the contribution of Ca-P to inorganic P pool and organic P to total P pool increased. The results also indicated Al-P, Fe-P and O-P controlled P availability in wetlands with RFL age. The changes of soil P contents, composition, and availability were attributed to soil clay content, and shift of hydrological condition and recovery status of vegetation after RFL.