To evaluate the efficacy of the Ahmed Glaucoma Valve implant in the treatment of refractory glaucoma.28 cases(29 eyes) of refractory glacucoma were treated by the Ahmed glaucoma Valve implant, including 10 cases (10 eyes) of neovascula glaucoma, 5 cases (6 eyes) of juvenile glaucoma and 13 cases (13 eyes) of other causes glaucoma.Post-operative follow-up time was 3-12 months. The intraocular pressure (IOP) was lowered from preoperative 40.9 +/- 7.32 mmHg (1 mmHg = 0.133 kPa) to postoperative 20.63 +/- 2.75 mmHg in Neovascular glaucoma; from preoperative 41 +/- 5.66 to postoperative 18.00 +/- 2.12 mmHg in glaucoma after IOL implant combined with vitrectomy operation; from preoperative 33.65 +/- 5.28 to postoperative 16.45 +/- 1.48 mmHg in juvenile glaucoma; from preoperative 31.43 +/- 4.13 to postoperative 18.13 +/- 1.25 mmHg in the failure conventional filtering surgery of glaucoma. The postoperative complicatons were flat anterior chamber, hyphema, anterior iritis and so on.The Ahmed glaucoma valve implant is a useful method in lowing IOP of refractory glaucoma.