Abstract: The Informal Tacit Knowledge Transferring（ITKT）is the main way of organizational tacit knowledge transferring, and is significance for the development of organizational core competitive competence and technological innovation competence. The knowledge transferring is divided into four types based on the characters of knowledge and its concrete transferring way, namely, formal explicit knowledge transferring, informal explicit knowledge transferring, formal tacit knowledge transferring, and informal tacit knowledge transferring; and their characters are compared. Then, the process mechanism of the informal tacit knowledge transferring among organizations is researcned from views of inter-individuals, between individual and group, between individual and organization, inter-groups, and between group and organization; based on that, tacit knowledge can be divided into true tacit knowledge and false tacit knowledge. In the end, the process model is set up, and the realization conditions are put forward.

Key words: ITKT, informal knowledge transferring, tacit knowledge transferring, model of knowledge transferring