In order to find the feasibility or intercropping basis of Allium mongolicum and Raphanus sativus, this paper studied the effects of growth and physiological index of R. sativus under treatments of A. mongolicum, which concentration of the external extract was 5-20 g/L. The results showed that: The roots weight, the soluble protein content, free proline content, SOD activity and CAT activity of R. sativus were all promoted by allelopathy when the A.mongolicum extract content was 5 g/L. When the A. mongolicum extract content was 20 g/L, the number of leaves and the the diameter of root were promoted in the period of and cortex splitting stage and harvest stage. The content of soluble sugar of all the treatments did not change significantly. In conclusion, the extract of 5 g/L A. mongolicum can promote the growth and yield of R. sativus to a certain extent, and maintain the activity of antioxidant enzymes in radish, without causing membrane lipid peroxidation and nutrient loss. There is a certain possibility of the feasibility or intercropping of A. mongolicum and R. sativus,