Tacit knowledge is a promoter of success for an architectural engineering project. Tacit knowledge sharing and transfer between members are difficult and complex for members of an architectural engineering project come from different fields. In this paper, we attempt to explore how tacit knowledge can be utilized effectively in an architectural engineering project. A model is presented by which tacit knowledge sharing and transfer can be understood profoundly in an architectural engineering project. A rational mechanism of tacit knowledge sharing and transfer is addressed: establishing better cooperation atmosphere and environment, improving inspiriting & performance evaluation mechanism and promoting tacit knowledge sharing and transfer by information technology.