Abstract: For detecting the resistance of varieties of peanut against leaf scab, the seedlings of 32 varieties were inoculated with the spore of scab pathogen, and the observation on the disease development in the field was systematically carried out. The results showed that 11 varieties, including Eyou 5 and Huaihua 8, were susceptible; 10 varieties, including Puhua 16 and Jinhuasheng 1, were moderate susceptible; 8 varieties, including Eyou 9 and Huaihua 8, were moderate resistant; 3 varieties, including Xuhua 8 and G/845, were resistant. The results of differents parts of leaves from the cirruses of 8 varieties revealed that the incidence of a disease, the top leaf of the MR-R varieties， was 0%-23.8%, the rate of the diseased leaf belonging to the V、VI degrees；while the MS-S varieties ，the incidence of a disease is 84.0%-100% and 10.7%-37.1%.The results of leaf activities of enzyme and the content tests of MDA of different disease levels from different susceptible varieties revealed that activities of POD and the content tests of MDA raised accordingly and had close relation; while the activities of CAT and SOD descended .The results of micro-measure of different parts and phases revealed that the different reactions to scab pathogen were determined by the cortical structural differences of varieties. The resistant varieties and aging structures have thicker cutin, less stoma density in the leaf; The susceptible varieties and tender structures have thinner cutin, much stoma density in the leaf.