Compaired with treatment of acute lumber sprain with puncturing of acupoint of WeiZhong , 109 cases of acute lumber sprain were treated with stimulation of sciatic nerve by gross needle. Among 61 cases in gross needle Group, 57 were significantly effective , 4 were effective and no case showed ineffective . Among 48 cases in filiform needle guoup , 30 were significantly effective, 16 were effective and the other 2 were ineffective. There was significant difference between the gross needle group and the filiform needle group. It showed that there was clinical significance in treating of acute lumber sprain with stimulation of sciatic nerve by gross needle.