52 fetuses in frog position were diagnoed by uitrasonography to probe the occurence reason of frog position and its delivery outcome was compared with the delivery outcome of not-frog-position group. Results: in frog position group, normal delivery rate was 8o. 8％,dystocia rate was 19．2％;in not-frog-position group, normal delivery rate was 65. 4％, dystocia rate was 34.6% (P
