Objective To evaluate the analgesic effect of oxycodone hydrochloride and morphine in preemptive analgesia for abdominal surgery.Methods The 200 patients who received abdominal operation were randomly divided into the oxycodone hydrochloride group (group O) and the morphine group(group M) with 100 patients in each group,and patients of the two groups were given oxycodone hydrochloride and morphine in preemptive analgesia respectively .The VAS, OAA/S and BCS 48 hours after surgery , the frequency of the use of PCIA in 24 hours,the satisfaction of patients ,and the occurrence rate of complications were compared between the two groups .Results There was no significant difference between the two groups in VAS ,BCS,OAA/S,frequency of the use of PCIA and patients satisfaction (P>0.05).The occurrence rate of nausea,vomit,and itch in group O were much lower than that in group M (P<0.05).The occurrence rate of drowsiness in group O was higher than that of group M(P<0.05).Conclusion Compared with morphine,oxycodone hydrochloride has the same analgesia efficiency and less side effect occurrence rate for patients with abdominal operation .