Influence of compound pollution of Rac-metolachlor or S-metolachlor with Cd on soil catalase and dehydrogenase activity was studied in laboratory. Rac-metolachlor and S-metolachlor were added separately to the tested soil at a dosage (6.8 mg kg^-1) recommended for crop field and at a dosage (68 mg kg^-1) ten times of the recommended one; Cd was designed to have three different concentrations (0, 50, 100 mg kg^-1). Catalase and dehydrogenase activities were tested under single stress of Rac-metolachlor or S-metolachlor and its combination with Cd. Difference between Rac-metolachlor and S-metolachlor in enantioselectivity towards catalase and dehydrogenase activities was also investigated. Results indicate that stress of Rac-metolachlor or S-metolachlor was imposed, catalase activity was first enhanced and then inhibited; while dehydrogenase activity followed a similar trend, but eventually rose up again Rac-metolachlor and S-metolachlor showed different enantioselectivity toward catalase activity, while no significant difference was found in enantioselectivity toward dehydrogenase activity. Under the combined pollution of Rac-metolachlor or S-metolachlor with Cd, catalase and dehydrogenase activities showed the same trend as under the single metolachlor pollution. With the same level of metolachlor, catalase and dehydrogenase activities were greatly influenced by increase in concentration of Cd， showing that compound pollution of metolachlor and Cd had certain interaction effect on catalase and dehydrogenase activities.