Abstract： Objective To study the effect and side - effect of pethidine intramuscular injection combined with unarmed cervical expansion on stages of labor.Methods A total of 120 normal primiparas were divided randomly into two groups.60 primiparas served as the experimental group ( Group A) and received pethidine intramuscular injection and unarmed cervical expansion ; 60 primiparas were measured as the control group ( Group B ) ,treated with normal care.There was no statistical significance in primiparas in two groups with age,weight,gestational weeks and fetal head size ( P ＞ 0.05 ).Stages of labor,pain rating scales of puerperas,fetal distress and postpartum hemorrhage were observed.Results Both of active phase and second stage of labor were shorten ed in group A.The cases of normal delivery increased in group A than that in group B.There were significant differences between two groups.Conclusions Pethidine intramuscular injection combined with unarmed cervical expansion can shorten active phase and second stage of labor,reduce postpartum hemorrhage,abate pain of puerperas,decrease fetal distress and asphyxia neonatorum and decrease rate of caesarean section.