Abstract: The inhibition and the toxicity of Cynanchum komarovii extracting solution on the growth of rice blast and gray mold were studied. The results showed that it inhibited the growth of two germs, and with the extracting solution density elevate, the repressing function on the growth of the two germs was also strengthened correspondingly; The adhesive material adhered to extracting solution did not rise the function of strengthening its self-restraint to the rice blast germ growth, but low density extracting solution of Cynanchum komarovii added adhesive material strengthened the repressing function on the growth of gray mold, however, such function were not notable to the high density Cynanchum komarovii.