A capital structure may not be stable due to several reasons, i.e. the change in its status, the change in regulation, and others. Such changes cause the relationship among the variables also alter. Under this condition, empirical studies have to adjust the length of period to assure the validity of the analysis. This study attempts to investigate the change in the Indonesian capital structure. Chow test and other analysis lead to the conclusion that the capital structure has changed and affected the relationship among market variables.