To investigate the effect of psychological suggestion therapy on the birth process, a specially designed, prospective study of psychological suggestion ("insubstantial comfort") was undertaken in 120 healthy, full-term primipara with singleton pregnancy and cephalic presentation. All cases were randomly divided into 2 groups, the birth processes and final modes of delivery were analyzed in 60 cases interfered with the psychological suggestion therapy and 60 cases with spontaneous birth processes as control group. The results showed that a significant shorter time of the first and second stages of labor in the study group than that in the control group (P < 0.01). Based on this study, it is suggested that the conversation concerning about the evaluation of individual birth process between the mother-to-be and nurse should be controlled carefully for the purpose of advancing of birth process. The nurse should apply the psychological suggestion therapy during the birth process, specially when answering the question raised by mother-to-be about the quantity of the cervical dilataion. It is also suggested that the purpose of the rectal examination taking during the first stage of labor should be given some kind of meaning of psychotherapy.