Objective:To evaluate the analgesic effects of two kinds of preoperative peripheral nerve block drug in patients with tri-geminal neuralgia undergoing radiofrequency thermocoagulation(RFT)of gasserian ganglion.Methods:90 patients with classic trigemi-nal neuralgia of the 3rd branch were scheduled to undergo RFT of the gasserian ganglion and were randomly divided into 3 groups(n =30).The patients in group N without nerve block were served as the controls.The patients in group A and B were treated by the nerve block of inferior alveloar with 2 ml of 2% lidocaine hydrochloride and 2 ml of compound lidocaine hydrochloride for each respectively 2 d before RFT.The pain control was studied by VAS method before and 24,48 h after nerve blocking and during pucture for RFT.Re-sults:Compared with the control group,24 h after nerve blocking,the average pain and the most pain VAS value of group A and B were significantly reduced(P <0.01);sleep quality and analgesia satisfaction were improved in group A and B(P <0.05).48 h after nerve blocking the pain relief and sleep quality improvement of group B were more than those of group A(P <0.05).In addition,during RFT puncture the pain intensity of group A and B were less than that of group N(P <0.05).The pain control in group B was more effective than that in group A.Conclusion:A single peripheral nerve block with long-term narcotic compound lidocaine hydrochloride can be an effective way to relieve preoperative and operative pain for RFT of trigeminal neuralgia.