【Objective】 The transcription factor ERFs have various biological functions, and play important roles in regulating plant growth and development and responding to stress. Previous studies have shown that SmERF1 from Salvia miltiorrhiza, participated in plant response to stress. To further elucidate the potential functions of SmERF1, and to further lay a foundation for the study of resistance and seed development of medicinal plants. 【Methods】SmERF1 was hetero-expressed in the model plant tobacco mediated by Agrobacterium tumefaciens in this study. The resistance of transgenic plants was evaluated through determining the plant resistance-related enzyme activity. The levels of hormones such as GA and ABA, were analyzed using enzyme-linked immunosorbent assay, and the expression changes of key enzyme genes involved in hormone biosynthesis were detected with qPCR methods. 【Results】 The results showed that: (1) SmERF1-expressing tobacco plants showed slower growth, less biomass and a decrease in chlorophyll only at the seedling stage with no significant difference in other growth stages. In addition, seeds of tobacco plants with SmERF1 expressed were smaller and lighter than those of wild plants. (2) Under NaCl treatment, the transgenic tobacco lines showed better tolerance to salinity, and the proline content, SOD and POD activities of transgenic lines were higher than those of wild-type plants, while MDA content was lower than that of wild-type plants. (3) we determined the phytohormones related to plant resistance, and the results showed that transgenic tobacco plants had higher ABA levels but lower GA levels as compared to wild type plants. The expression of SmERF1 regulated the expression of key enzyme genes related to plant hormone biosynthesis, such as NtSDR, NtGA20ox, NtACO and NtACS. 【Conclusion】 This study suggests that SmERF1 enhanced tobacco tolerance to salt and regulated seed size through the ABA-dependent pathway.