It is an important function the continuing business relation which spares cooperation and collaboration based on trusting in a long time to form the reciprocal cross shareholding. The crossshare holding and continuing business relation have the interaction as an interdependent relationship. The cross shareholding of Japanese company is decreasing in an accelerating degree after 1990. The factors of decreasing are mainly new institutional introduction such as a market price accounting system, a rise of risk awareness with stock price crash and weakening of a continual business relation between the enterprise. It`s possible to say that new institutional introduction acted on decrease of cross share holding more directly. However I should say that weakening of a continuing business relation between the enterprise based of a share holding acted on it the most fundamentally. Such decrease of share holding and weakening phenomenon of continuing business relation suggest that a Japanese market has changed from continuing business relation focused on cooperation and collaboration based on trusting to the emphasized market business relation focused on competition largely. In other words, the Japanese market evaluated exclusively has being greatly changed to the open market. Decrease of cross shareholding and weakening of a continuing business relation are expected to accelerated more through the interaction.