The cultivated soybean varieties are moderate tolerant under salt stress, but soil salinization seriously threats thesoybean yield and quality. Characterization of the salt-tolerant genes might be suitable for the genetic improvement of salt tolerance. In eukaryotes, transcription factor IIIC (TFIIIC) generally interacts with transcription factor IIIB (TFIIIB) on RNA polymerase III to regulate tRNA gene transcription, which in turn affects protein synthesis. In our previous study, we found that TFIIIC was up-regulated in soybean root under salt stress. However, the gene function of GmTFIIIC remains unknown under high salinity stress. In this study, we characterized the GmTFIIIC function in transgenic complex, in which the GmTFIIIC over-expression was conducted by transforming the soybean hairy roots. The results showed that the Na+/K+ of roots and shoots in the GmTFIIIC overexpression complex were lower than that in the vacant control complex. While the relative content of chlorophyll and water in leaves was higher, and the content of H2O2 and O2- was lower than that of the vacant control complex, which indicates that the salt tolerance in transgenic complex is enhanced by GmTFIIIC overexpression. Thus, the results might contribute to a better understanding of the molecular mechanism of GmTFIIIC in responding to salt stress.