Objective To investigate the efficacy of microendoscopic tubular retractor system (METRx) in the management of lumbar intervertebral disc herniation. Methods By using the METRx system with modified instruments, the lumbar discectomy was performed in 550 cases. During the operation, patients were placed in a knee-chest sitting position, and the instrumentation was utilized into the vertebral canal through the ligamenta flava. Results The patients were followed for 6~36 months (mean, 21 months). According to the Nakai criteria, the curative outcomes were “excellent” in 478 cases (86.9%), “good” in 60 cases (10.9%),“fair” in 6 cases (1.1%), and “poor” in 6 cases (1.1%). The 6 cases with “poor” results obtained “fair” results after a re-operation of lateral recess enlargement and residual nucleus removal under microendoscope. Conclusions Lumbar discectomy with the utilization of the METRx system is minimally invasive, safe and effective.