The ultra length and width random calf fasciocutaneous flaps whose blood supply came from the calf fasciocutaneous vascular network were transposed in 9 cases for the treatment of severe trauma of leg. All of the flaps survived except one having necrosis of the distal fourth. The length and width of the flap to the width of the pedicle were 6.1∶1 and 2.7∶1 respectively. Properly extended the area and decreased of blood perfusion of the flan would reduce the burden of the venous backflow to the flap relatively. The abundant vascular networks of the calf fasciocutaneous flap was a very important factor that this type of flap would possibly survive.