Abstract: OBJECTIVE To evaluate the safety and efficacy of Timolol Maleate Sustained-release Eye Drop(new) in the treatment of primary open angle glaucoma. METHODS This was a 12-week multi-center, randomized, double-blind, parallel group, non-inferiority clinical trial. The trial enrolled 240 subjects with primary open angle glaucoma. Subjects were randomized to test Timolol Maleate Sustained-release Eye Drop(new) group and control (traditional timolol eye drops) group by 1∶1. The clinical effect of drugs in the two groups were recorded and analyzed comparatively. RESULTS There were 204 subjects in the per protocol set. These difference were statistically insignificant between pre-exposure and post-exposure average levels of lowing intraocular pressure(P<0.05). The comparision between two groups were revealed as no significant difference in statistics on every observation moments of time. There were 229 subjects in the safety set. The 32 cases of adverse events in the safety set mainly included eye reactions and slow heart rate. CONCLUSION The efficacy of Timolol Maleate Sustained-release Eye Drop(new) treatment in primary open angle glaucoma is similar with that of traditional timolol eye drops, and it is worthy of clinical application for its lower toxicity induced by its solvent and convenience of usage.