Abstract: In the study,the extraction from stem and leaf of alfalfa was used to investigate the Allelopathic Effect on Germination and Seedling Growth of triticale.The result indicated that the concentration of extract can restrain germination of triticale seed to a certain degree,the inhibition also enhanced as the concentration of extract increased;the weight change in root,stem and leaf of triticale was increased firstly,and then decreased as the concentration of extract increased;when the extraction concentration was 20%,the effect to growth speed and height of triticale was the most significant.