Intelligent prosthesis is going to be a research focus recently with the increment of the transfemoral amputees and the development of microelectronic technology, control technology and so on. As the fundamental part of the lower extremity prosthetics, the knee prostheses with high performance is still hard to design. This paper reviewed the development of the intelligent knee prostheses, classified the current available prostheses in the term of construction design, and discussed the drawback of their design and the trend of the further development.