Abstract: The inhibition and the toxicity of lanthanum on the growth of Fusarium solani were studied, and the effect of lanthanum on three disease-related enzymes were researched too. The results showed that lanthanum inhibit the growth of Fusarium solani strongly, it's EC50 and EC95 were 278.2 and 552.0 mg/L respectively. Lanthanum also gives some effect on the disease-related enzyme of pathogen, it promote the activity of these enzymes such as pectinase, protease and cellulase, but for the strong inhibition of the growth of mycelium, the quantity or the activity of the total enzymes of pectinase was decreased significantly.