In order to modify the plastic operation for lumbar spinostenosis, [symbol: see text]-shaped splitting of spinous process was designed. Fifty-six patients with lumbar spinostenosis were treated. There were 36 males and 16 females, age ranged from 32-67 years old (with an average of 48.9 years old). Among them, 8 patients operation on L2-L5 segments, 16 on L3-L5 segments and 22 patients on L4-L5 segments. After operation, 32 cases were followed up from 8 to 27 months. The results were: 1. The result of operation was excellent in 21 cases, good in 8 fair in 2 and poor in 1. The effective rate was 90.6%. 2. The rate of bony union from laminectomy was 95.1%. 3. The sagittal diameter and transverse diameter of the spinal canal were enlarged in an average of 6.4 mm and 3.2 mm, respectively, with a mean enlargement of 37.6%. The conclusion were that the plastic operation with [symbol: see text]-shaped splitting of spinous process for lumbar spinal canal was easy to handle and it could effectively prevent the lumbar instability and secondary stenosis following operation.