To observed the Clinical effect of ropivacaine (Rop) of different concentration used for analgesia of labor, and ex plore the ideal concentration and dosage. Methods: 45 case s of ASA Ⅰ-Ⅱ primiparae nearing labor were vandomly divided three groups rand omly (0.16% Rop group, 0.2% Rop group were assigned 15 cases). The analgesia, in which the cervical os had opened up to 2-3cm; the controlled group was not giv en the analgesia of labor. BP, SpO2, EKG, PETCO2, cerrical contraction , fetal cardiac sounds were monitored continuously in the perinatal analgesia pe riod. The analgesia effects were determined by giving a mark for pain by VAPS, motor nerve blockings were given amark by Bromage scale; Apgar scale were conduc ted 1-5 min after neonates were labored out. Results: The vital signs of three groups were stable in perinatal; the VAPS scale was lower s ignificantly in observed group than in controlled group; while the blocking freq uency and extent of motor nerve were highest from 0.2% Rop, which had light inhi bitory effect to cervical contraction, causing the dosage of oxytocin to increas e relatively; the NACS scale 24 h after labor was more increased significantly in observed group than controlled group. Conclusion: The un ique blockings to sense and motor were obviously separate, having no obvious eff ect to blood stream of uterus and placenta, being benificial to analgesia in per inatal. The 0.16% Rop was a more ideal local anaesthesia agent than 0.2% Rop .