Abstract: Objective: To observe the effects of different concentrations of isobaric bupivacaine anesthesia on procedure for prolapse and hemorrhoids(PPH).Methods: Ninty male patients with ASA Ⅰ ～ Ⅱ undergoing PPH were randomly divided into high,medium and low concentration groups(30 cases each group).The three groups were injected with 0.50%,0.25% and 0.15% of isobaric bupivacaine, respectively.The levels of BP,HR and SpO2 of three groups were recorded in 10 minutes before and after anesthesia.The onset time and highest level of sense block of anesthesia, the motor nerve block degree and duration and the intraoperative anal relaxation degree and rectal guyed reflection were detected.The postoperative adverse reactions were followed up.Results: There were no significant differences between the onset time and highest level of sense block of anesthesia and rectal guyed reflection in three groups(P ＞ 0.05).The motor nerve block degree and duration and the occurrence rate of the urine retention of high concentration group were higher than those in other two groups(P＜0.05 to P＜0.01).The anal relaxation degree of low concentration group was lower than that of high concentration group(P＜0.05).Conclusions: The 0.25%of isobaric bupivacaine anesthesia can meet the needs of PPH.