Abstract: 17 cases of birth canal hematoma were reported in this article.It was analyzed with relative risk method.The results showed that thrombocytopenia,anemia,EPHsyndrome,prolonged labor.Fatty were the factors which lead to birth canal hematoma,so that we must examine them carefully after the delivery.The typical symptom was painful in anus area within severl hours after labor. If it extended into broad ligament,there was painful in the same lateral lower abdomen.The treatment of fresh hematoma is exposure it,taking off the blood clot,hemostasis and then close up it. Longitudinal incision is convenient to expose its cavity and to seek for bleeding points.If bleeding cannot be stopped completely,pad is needed for tamponing.Epidural anesthesia is useful when hemotma is located in the upper segment of vagina.In order to prevent infection, plenty of antibiotics was given after the operation.Treatment can prevent from infection and the hematoma would be absorbed spontanously.

Key words: birth canal hematoma, relative risk thrombocytopenia