Unlocking disease resistance to exotic maize germplasm is the basis and premise for the fully utilization of germplasm and breeding ofresistant varieties. In this study, resistance evaluation of 149 American inbred lines to maize stalk rots induced by four different pathogens, including Fusarium graminearum, F. verticillioides, F. proliferatum and Pythium aristosporum, were conducted by artificial inoculation in continuous two years from 2017 to 2018. And, 30 resistant materials and six backbone inbred lines were selected for genetic diversity analysis. The results showed that among the 149 American inbred lines, 62, 44, 41, and 54 materials exhibited moderate resistance (MR) or higher resistance levels to maize stalk rots caused by F. graminearum, F. verticillioides, F. proliferatum and P. aristosporum, respectively. There were 23 inbred lines showing high resistance (HR) for all four stalk rots, 32 inbred lines showing MR or higher resistance levels for all four stalk rots, and 27 inbred lines showing HR for three Fusarium stalk rots. Among the tested materials, 88 inbred lines showed the same level of resistance to all four stalk rots, 61 inbred lines had different resistance to all four stalk rots. Twenty polymorphic primers were screened, and 5~11 alleles were detected with each primer, and the average allelic variation was 7.7. Thirty-six materials were divided into 6 groups by cluster analysis, Among them, 2FACC, J8608 and Huangzaosi were separately clustered into three groups, and the other inbred lines were divided into three groups, each group consisting of 26, 5 and 2 inbred lines, and the first group was further divided into three subgroups. The results of this study clarified the differences in resistance of exotic American inbred lines to maize stalk rot caused by different pathogens, and provided a reference for the selection of resistant sources in resistance breeding.