【Objective】To evaluate the analgesic efficacy of erector spinae plane block（ESPB）in patients undergoing robotassisted partial nephrectomy（RAPN）. 【Methods】One hundred patients scheduled for RAPN were randomized into ESPB group（Group E）and thoracic paravertebral block（TPVB）group（Group T），with 50 cases in each group. Ultrasound-guided nerve block was performed by senior experienced anesthesiologists in both groups. All patients received 0.5% ropivacaine hydrochloride and postoperative patient controlled intravenous analgesia （PCIA）. The imaging time， needling time，number of needle passes，difficulty scale，consumption of remifentanil and propofol，pain visual analog scale（VAS）scores at rest and movement within 24 hours after surgery，pressing frequency of PCIA pump，postoperative complications and patients′ satisfaction with analgesic efficacy were assessed and recorded. 【Results】Compared with TPVB，ESPB required significantly shorter imaging time and needling time，significantly fewer number of needle passes and lower difficulty scale（P < 0.001）. No significant difference was observed in term of the rest parameters between two groups（P > 0.05）.【Conclusion】Pre-emptive ultrasound-guided ESPB results in similar analgesic efficacy with TPVB in patients undergoing RAPN. ESPB may be easier for the junior doctors to perform due to its apparent superiority.