- This article introduces a novel protein structure alignment method (named TALI) based on protein backbone torsion angle instead of the more traditional distance matrix. Representing protein structure by a serial backbone torsion angles (, ), protein structure have a simple mapping relationship to protein sequence. Thus, TALI can naturally incorporate sequence information and sequence analysis method into structure comparison. Here we report the result of TALI in comparison to other structure alignment methods such as DALI, CE and SSM as well as sequence alignment based on PSI-BLAST. TALI demonstrated great success over all other distance based methods in application to challenging remote homologous proteins. Finally, successful inference of phylogeny tree of class II amonoacyl-tRNA synthetase shows the capability of TALI in estimating the protein structure evolution.