Objective   To evaluate renal hemodynamics in patients with single renal calculi during perioperative period of flexible ureteroscopic lithotripsy by color Doppler flow imaging (CDFI).   Methods  The hemodynamic of renal interlobar arteries of 61 patients with one renal calculi who underwent unilateral flexible ureteroscope lithotripsy from Jul. 2016 to Jun. 2018 were examined separately  prior to surgery  (Day 1) and after surgery (1 hour and Day 5) by CDFI. Parameters were analyzed statistically.    Results    There were significant differences in systolic flow (Vmax), diastolic flow (Vmin) and resistance index (RI) during perioperative period (P＜0.05). 1 h after operation, a statistically significant decrease of Vmax and Vmin, and increase of RI of renal interlobar arterial were found compared with preoperative measurements (P＜0.017). In the follow-up of 5 d after operation, Vmax and Vmin were higher than 1 h after operation, and RI was lower than 1 h after operation (P＜0.017). There was no significant difference between preoperative measurements and 5 d after operation(P＞0.017).   Conclusions   CDFI can be used to quantify the blood perfusion in kidney after flexible ureteroscope lithotripsy. Renal Vmax and Vmin decreasing and RI increasing can be found in a short timeframe during perioperative period, and the changes are reversible.