Objective To evaluate the 25-gauge (25G) transconjunctival sutureless vitrectomy system (TSV25G) for macular diseases. Methods The clinical data of 18 patients with macular diseases treated by the TSV25G were retrospectively analyzed. The 18 patients included 13 men and 5 women, aged from 25 to 73 years. The disease course ranged from 3.5 to 10 months, in cluding 8 epiretinal membrane, 3 idiopathic macular hole, 3 tranumatic macular hole with submacular heamorrhage, 2 vitreo-macular tractional syntrome and 2 diabetic macular edema. The surgical parameter installation was as follows: high speed cutter with rate of 1500 cuts per minute; the maximum aspiration with a TSV2 5G were 500-550 mmHg (1 mm Hg=0.133 kPa); the BSS bottle height was 40-50 cm; the intraocular pressure was 29-35 mmHg during the surgery. The postoperative follow-up period was 2.5-10 months. Results Eighteen patients had undergone the vitrectomy successfully with the operative time of 26-44 minutes (mean 35 minutes). No complication was found. Water leakage of the puncture site was found in 1 patient and was sewed up with 8-0 absorbable sutures. The mean time of inpatients were 3.5 days postoperatively. In the postoperative follow-up in 18 patients, the macular edema disappeared totally in 12 patients 3-6 months after the operation; the visual distortion disappeared in 10 and alleviated in 2; the visual acuity regained (0.8 or more) in 6 (33.3%), not changed in 4, and improved in 2. Conclusion TSV25G was safe, time-saving, and effective for macular diseases. (Chin J Ocul Fundus Dis，2004，20：137-138)