When the patient has anaemia, pulse, faint cold, the fetal heart sounds abnormity or disappear, high uterine tone, ultrasound show fluid dark section back placenta, in late pregnancy, we bethink of placental abruption. 结论除典型疼痛性阴道出血外,妊娠晚期不明原因贫血、脉快、厥冷伴胎心异常或消失、高张性子宫、B超显示胎盘后液性暗区均有助本病诊断。