In the selection of calf prosthesis should consider the following factors: 1, the length of the residual limb: long residual limb is easy to feel cold in winter, should not choose aluminum calf, optional skin calf or modern calf above the knee with suspension type of calf (called patellar ligament bearing calf prosthesis, referred to as PTB calf); in or short residual limb can choose to accept the cavity can hold the widest part of the knee type (called condylar insert wedge calf prosthesis, referred to as KBM calf ); or choose to hold the patella (known as the knee-covered calf prosthesis, referred to as PTES calf). 2, the residual limb weight-bearing capacity, whether the knee joint is stable: when the knee joint is unstable, the residual limb is short, the skin scar area is large, the weight-bearing function is not good, then the calf prosthesis with metal knee hinges, thighs should be used. 3, age: the elderly should choose lightweight prosthesis; young, like sports people should choose universal prosthetic foot or energy storage prosthesis; children’s prosthesis should be selected every year can easily increase the length of the lower leg and replace the residual limb receiving cavity prosthesis. (The special problem of children’s prosthesis: children due to the growth of healthy limbs, prosthetic acceptor cavity need to be replaced once every six months; prosthetic limbs need to be replaced once every 1 or 2 years). 4, the surrounding environment, occupation, financial ability, maintenance conditions: if the amputee lives in rural areas, engaged in agricultural labor to choose traditional prosthesis or practical, inexpensive popular calf is appropriate, such prostheses are cheap, but also easy to maintain their own.