Abstract: Objective To study the therapeutic effect of transverse carpal ligament release on carpal tunnel syndrome （CTS） with arthroscopic" two-portal" technique. Methods Transverse carpal ligament was released with arthroscopic" two-portal" technique for 31 patients （36 wrists） in November 2002-December 2008. The patients were followed up for 1-7 years （mean 39 months）. Results The Kelly score was excellent, good, and fair for 20（23 wrists）, 7（9 wrists）, and 1 patients, respectively, among the 28 patients（33 wrists） who were followed up. No complications such as median nerve injury and adhesion occurred. Conclusion Arthroscopic "two-portal" technique is an effective surgical procedure for transverse carpal ligament release with minimal incision, less tissue trauma, and shorter operation time.