Abstract: In order to reveal the response mechanism of the symbiont of Potentilla sericea-arbuscular mycorrhizal fungi to cadmium stress at the physiological level,the perennial plants of P.sericea were inoculated with Rhizophagus intraradices and Funneliformis mosseae respectively.The mycorrhizal infection rate was determined with different concentrations of cadmium stress after 80 d,and the changes of physiological indexes and structural changes of symbiosis plants with higher infection rate was studied.The results showed that the mycorrhizal infection rate of F.mosseae was 100%higher than that of R.intraradices,while the infection rate of R.intraradices was 89.33%.Plants inoculated with F.mosseae,when the concentration of Cd reached10 mg·L^-1,the cell wall ruptured in a small range and the vacuoles tended to become smaller,and when the concentration of Cd(20 mg·L^-1)was high,the root cell wall ruptured and the cells could not maintain their original morphology.The MDA content of Cd(5 mg·L^-1)-Cd(10 mg·L^-1)was significantly increased（P＜0.05）,and the SOD activity and proline content of Cd(0mg·L^-1)-Cd(5mg·L^-1)were significantly changed（P＜0.05）.The soluble protein content and chlorophyll content of Cd(0 mg·L^-1)-Cd(5 mg·L^-1)were significantly decreased（P＜0.05）,but the soluble protein content and chlorophyll content of Cd(10 mg·L^-1)-Cd(15 mg·L^-1)had no significant changes（P＞0.05）.The results showed that plant could resist cadmium stress in a certain range.In conclusion,inoculation with F.mosseae could enhance the stress tolerance of P.sericea to cadmium stress,which provided a theoretical basis for the remediation with P.sericea of soil contaminated by cadmium.