Glutathione S-transferases (GSTs) are superfamily of multifunctional enzymes which play important roles in stress tolerance and cellular detoxification. In this paper, a GST gene named BnGSTU1 (GenBank accession: MG941011) was isolated from ramie (Boehmeria nivea L.) by amplification of cDNA ends (RACE) based on the analysis of expression profiling of cadmium response genes in ramie. The open reading frame of BnGSTU1 is 636 bp, which encodes 211 amino acid residues. The predicted protein was 24.07 kD with isoelectic point of 5.29. Conserved domain search analysis revealed that BnGSTU1 protein contained a N-teminal domain and a C-teminal domain, as well as glutathione binding sites G and substrate binding pockets H, which showed typical characteristics of Tau class GSTs. Phylogenetic tree analysis showed that BnGSTU1 was closely to Tau class GST in Arabidopsis thaliana, Hevea brasiliensis and so on. Real-time quantitative PCR analysis indicated that BnGSTU1 expressed in root, stem and leaf of ramie, but the expression level of BnGSTU1 in leaf was significantly higher than that in roots. Furthermore, BnGSTU1 gene was significantly induced by cadmium stress, and the expression of BnGSTU1 increased along with Cd2+ concentration. Collectively, the results suggest that BnGSTU1 is a cadmium-responsive factor and may play potential roles in the plant adaption to cadmium stress.