The tolerance and physiological response to crown gall of six types of cherry rootstocks seedings in Guizhou Province were investigated using inoculating experiment.The results showed that:(1)The disease incidence of Qingyan cherry seeding was only 6.67%,and its average tumor diameter and tolerance ratio were 1.76 mm and 6.67,respectively,demonstrating the highest tolerance to this disease.However,Yanhe cherry demonstrated the lowest tolerance with 50.0% of disease incidence,6.43 mm of tumor diameter,as well as 33.76 of tolerance ratio.(2)Obvious physiological responses were obtained after the incidence of this disease.The content of free proline in leaf considerably increased,as well as the activities of peroxidase (POD) and superoxide dismutase (SOD) were enhanced.Conversely the catalase (CAT) activity went down.Free proline content of the Qingyan cherry increased amplitude,and protective enzymes of Yanhe cherry were significantly changed.(3)The disease incidence was closely correlated with the tolerance ratio and SOD activity,with correlation coefficient was 0.98 and 0.86 respectively.Also the tolerance ratio was closely correlated with the activities of POD (r=0.82^*) and SOD (r=0.83^*).Obviously the tolerance to crown gall of six types of cherry rootstocks seedings was significant different,and Qingyan cherry demonstrated the highest tolerance.The resistance was closely related with the content of free proline ,as well as the increase of POD and SOD activities.