Tryptophanyl-tRNA synthetase (TrpRS) plays a pivotal role in protein synthesis. However, till now no stereostructural data of Bacillus subtilis TrpRS were reported. Here, by using the homology modeling using Bacillus stearothermophilus TrpRS as a template, it is demonstrated that the synthetase has 16alpha helices and 5beta sheets. The only tryptophan Trp(92) is located on the interface of subunits. Also the modeling presents the ligand binding site, active site and the putative binding of tRNA(Trp).