Fast awakening from anesthesia is one of the major characteristics of remifentanil-associated anesthetic induction and maintenance, whereas corresponding pain during awakening influences patient's rehabilitation strongly. In addition, such early postoperative pain results in significant stress responses, which displays as further release of stress hormones such as cortisol and β-endorphin as well. How to prevent such acute pain resulting from remifentanil's fast metabolism endows clinical significance. This study is designed to compare the analgesic efficacy of fentanyl, sufentanil and butorphanol delivered after gynecological laparoscopic surgeries that underwent remifentanil induction and maintenance, and investigate corresponding influence on the levels of blood cortisol and β-endorphin.