Abstract: The Children of twelve years old， twin lower legs and feet arise bruising, blood blisters, erosions and necrosis with pain 2 + months, Specialist: There is some symmetrical, petechiae, a large bruis， blood blisters, erosions, ulcers, necrosis, crusting,and more bloody discharge on both legs and feet, tenderness evidently. Histopathology: Livedoid Vasculopathy. the pain and bruising subsided, healing of ulcers with Low molecular weight heparin 0.6ml ih qdX7 days; significant effectly, such treatment has not been reported in the country.