This research aims at exploring the interaction and differences of the relations among knowledge protection, relationship capital, strategic attribute of knowledge, and alliance performance. Through a mail survey, 95 effective samples of cross-border learning alliances of Taiwanese hi-tech firms were collected and analyzed. Using regression and simultaneous equations models, the proposed model was tested. The main conclusions are presented as follows: 1.Communication, trust, and commitment construct the determinants of relationship capital. 2.Knowledge which has more tacit, complexity, and special attributes is a more significant in strategic asset. 3.It is significant that the strategic attribute of knowledge will guarantee a influence on the relationship capital 4.It follows that the strategic attribute of knowledge that is transferred by alliances maintain a positive influence on knowledge protection by the target focus firm. 5.Relationship capital will guarantee a positive influence apparently on knowledge protection by the focus firm. 6.The higher the degree of relationship capital between alliance partners, the greater the alliance performance between the partners 7.It follows that the higher the degree of individual knowledge protection between alliance partners, the poorer the alliance performance between the partners.