Abstract:By using equal compartment agar method (ECAM), and through measuring the root length, shoot height, and rootand shoot dry weights of test ryegrass, this paper evaluated the allelopathic potentials of thirty-three wheat varieties with different origins in Northeast China against ryegrass. The results showed that different wheat varieties had significantly different allelopathic effects on ryegrass growth. With RI value as allelopathic index and through cluster analysis, these varieties could be divided into three groups, among which, four varieties (Longfu 9, Longfu 13, Jin 2003, and Xiaobing 33) were demonstrated to be obviously allelopathic, and inhibited the ryegrass growth strongly.