Abstract: Pot experiment was carried out to study the effect of arbuscular mycorrhizal fungus(G. mosseae) on phosphatase activity in the rhizosphere of clover(Trifolium pratense). The pots had three compartments, a central compartment for root growth was separatyed by 30 m mesh nets from two outer comparhoents for mycorrhizal hyphae growth. The outer compartments were filled with soils collected from field plots either receiving chemical fertilizer or manure in the long-term fertilizer experiment. For each the plants were inoculated with mycorrhizal fungus or remained uninoculated, respectively. The results showed that mycorrhizal infection significantly Stimulated plant growth. The activity of acid and alkaline phosphatase was increased in the hyphal growth compartment by mycorrhizal inoculation,especially in the case where the soil receiving manure was filled in the outer compartment. With histochemical technique. acid phosphatase activity was detected to be present around single hyphae, indicating that the arbuscular mycorrhizal hyphae are capable of releaseing phosphatase.