Using microbe bacteriostatic ring method,the extraction methods of garlic activity compounds antagonistic to tomato early blight（Alternaria solani） was studied.The results showed that the optimal extract conditions were as follows: First,the fresh garlic was crushed and digested by alliinase for 30～60 minutes incubation at 28 ℃.Then,the digested garlic was extracted by ethyl acetate at 28 ℃ for 12 hours with simultaneous shaking.Results of TLC and HPLC detection indicated that the main antifungal components were allicin and the volatile components have the highest antifungal activity.