Abstract: It is well known that plant heat shock proteins (HSPs) play important roles in response to adverse environmental conditions and there are cross-resistant mechanisms in their functions. We previously demonstrated that overexpressing ER-sHSP in transgenic tomato highly enhanced their abilities against cold stress. To continue improve our understanding about the physiological function of ER-sHSP, we assessed the salt-resistant ability of transgenic tomato plants under salt stress. Results showed that transgenic lines possessed higher fresh and dry weight, more proline content, higher SOD activity, lower MDA content, and lower relative electrical leakage. Transformed lines showed obvious resistance to salt stress compared to the non-transgenic lines. These results indicated that overexpression of ER-sHSP enhanced tolerance of transgenic tomato plants to salt stress.