We tried to induce cleft palate in Wistar rats by injecting Vitamin A. We injected Vitamin A into the stomach of females when they were pregnant on the eighth, ninth, tenth and eleventh day. We them sacrificed them to observe the fetuses while they were still pregnant on the eighteenth-twentieth day. The results showed that a high rate of cleft palate could be induced by injecting 5-10 x 10(4) I.U/kg of Vitamin A during pregnancy on the tenth day.