Abstract:To explore the virulence effect of all peaks’ protein compositions from different physiological races to tomato leaf, gel filter with liquid chromatography methods was used to purify toxin proteins secreted by six physiological races of tomato leaf mould pathogen and the bioassay was carried out by using needling leaf method. The results showed that only one peaks’protein compositions secreted by each physiological race could make the leaf chlorosis. These peaks’ protein compositions were from the fourth peaks’protein compositions of physiological race 1.2.3 (denoted 1.2.3(4), and the following analogy), 1.2.4(2), 1.2.3.4(2), 1.3(2), 1.3.4(2), 1.4(2). The cell ultrastructure of chlorosis tomato leaf observed under transmission electron microscope, and we found that chloroplasts were relaxed and swollen, and chloroplast grana were dissolved, especially treated by physiological race 1.2.3.4(2) peak’protein.