AIM:To observe the therapeutic effect of extra-trabeculotomy in treatment of primary infantile glaucoma (PIG). METHODS:A total of 23 cases (42 eyes )who were diagnosed with PIG and underwent extra-trabeculotomy in our hospital from January 2009 January 2011 were retrospectively analyzed. The intraocular pressure, corneal diameter and cup-disk ratio were observed. The follow-up period was 10-34 months. RESULTS:At the postoperative 1 week, the successful rate of extra-trabeculotomy was 88%. For those eyes with the follow-up more than 10 months, the intraocular pressure was significantly decreased, the cup-disk ratio was reduced, the corneal diameter unchanged and the successful rate was 84%. CONCLUSION:The glaucoma surgery of extra-trabeculotomy is an effective and optimal method for PIG for its high successful rate.