Abstract: Objective To observe the effect of propofol medium and long chain fat emulsion on hemodynamics, auditory evoked potential index and injection pain in small and short-time pediatric operation. Methods Fifty ASA Ⅰ-Ⅱ pediatric patients at the age of 3-6 years, admitted to our hospital from October 2011 to October 2012 for small and short-time operation, were randomly divided into propofol medium and long chain fat emulsion (MCT/LCT) anesthesia group (n=25)and propofol long chain fat emulsion(LCT) anesthesia group (n=25). Their hemodynamics, auditory evoked potential index and injection pain were observed before anesthesia, 1 and 5 min after anesthesia and after awake, respectively. Results No significant difference was found in hemodynamics, auditory evoked potential index and injection pain between the two groups (P＞ 0.05). The average score on the modified faces, legs, activity, cry and consolability (FLACC) scale was higher in LCT anesthesia group than in MCT/LCT anesthesia group (4.4±1.64 vs 3.04±1.50, P＜ 0.05). Conclusion The effect of propofol medium and long chain fat emulsion is similar to that of propofol, but the propofol medium injection pain of propofol medium and long chain fat emulsion is milder than that of propofol.