Abstract: Phosphorus (P) adsorption and desorption characteristics of surface soil (0 -10 cm) from 21-, 30-, 40-and 52-year-old larch plantations and undisturbed secondary forest were studied by analyzing their maximum adsorption amount (Qm ), maximum buffer capacity (MBC) and desorption rate, and other related soil properties in typical black soil region. Results showed that the extent and rate of P adsorption of larch plantations'soils were all higher than that of undisturbed secondary forest soil. Soil phosphorus Qm of larch plantations with different ages varied from 692.24 to 759.41 mg/ kg. Soil phosphorus Qm, adsorption intensity factor (K) and MBC of different larch plantations increased and then decreased with increasing stand age, and the values described above for 30-year-old were significantly the highest among four forests. The amount and rate of soil phosphorus desorption reduced firstly to the minimum at 30-year- old and then increased with increasing stand age to the maximum at 52-year-old larch plantation. Soil of larch plantation at 30-year-old had a strong phosphorus-fixation capacity; and 52-year-old larch plantation released easily phosphorus to soil, with the sorption and desorption capacity approaching to the levels of undisturbed black soil.