To explore the feasibility and effects of Cook balloon cervical dilator on full-term nulliparous parturients under epidural analgesia. The observation group(n=40)received Cook balloon cervical dilation under epidural analgesia. However, the control group (n=40) had no epidural analgesia. Latent phase of labor was shorter in observation group than that in control group [(198.7±65.7) vs. (242.9±78.9) min, P<0.05]. And the incidence of cesarean section and perineal laceration was lower under epidural analgesia(8% vs. 15%, 45% vs. 50% respectively). There were no effects on success rate of induced labor in neither group. Cook balloon could shorten latent phase of labor, relieve the pain of parturients and increase no infection rate [leukocyte count: (8.82±2.74) ×109 /L vs. (9.10±3.06) ×109/L, C-reactive protein: (4.73±0.87) mg/L vs. (4.82±0.90) mg/L respectively]. It is worth wider clinical popularization. Key words: Labor, induced; Analgesia, obstetrical