Abstract: Objective To investigate the value of preoperative multi-slice spiral CT angiography（MSCTA）and intraoperative ultrasound in laparoscopic occlusion of renal segmental arterial partial nephrectomy.Methods Forty-eight patients with small renal cell carcinoma underwent routine MSCTA examination.According to whether intraoperative ultrasound was performed，28 patients were divided into intraoperative ultrasound group and 27 patients without intraoperative ultrasound.The operation time，blood loss，intraoperative warm ischemia time，microscopic cancer discovery rate，transit opening rate，postoperative leakage of urine，positive margin of cutting edge and glomerular filtration rate（GFR）were measured.Results The intraoperative ultrasound group was better than the non-operative ultrasound group.The operation time was（172.1±3.5）min and（216.3±4.8）min，respectively；the intraoperative blood loss was（70.2±5.0）ml and（90.3±4.0）ml，respectively；the ischemic time was（24.5±4.2）min and（29.3±2.8）min，respectively，and the difference were all statistically significant（P<0.05）.The preoperative and postoperative renal GFR of the intraoperative ultrasound group were（55.1±7.2）ml/min and（54.1±7.7）ml/min（P>0.05），respectively.The non-operative ultrasound group had a renal GFR of（55.8±7.0）ml/min and（41.4±6.5）ml/min before and after surgery（P<0.05）.Conclusion Intraoperative ultrasound can quickly and accurately locate the tumor tissue，preserve the nephron as much as possible，reduce the positive rate of the margin，and facilitate the recovery of renal function after surgery.

Key words: small renal cell carcinoma, blocking renal artery, retroperitoneoscopic partial nephrectomy, multislice spiral CT angiography, intraoperative ultrasound