Pregnant rats were divided into four groups. The groups A, B and C were intraperitoneally injected with DPH during the 9 to 11 days of gestation in doses of 75 Mg/kg/day. The groups A and B were supplemented with a mixture of folic acid (FA) or with FA alone in the food fed during pregnancy. The results showed that DPH induced a significant decrease in the body weights and lengths of fetal rats (P less than 0.01), but induced an increase in the incidences of subcutaneous bleeding (P less than 0.05) as well as skeletal and internal malformation (P less than 0.05). The supplement of FA or a mixture of FA in the food fed during pregnancy exhibited partial preventive effects on DPH to induce teratogenicity. The effect of a mixture of FA was better than that with FA alone in reducing the incidences of internal abnormalities and agenesis of the bones of the distant phalanges and subcutaneous bleeding.