This thesis focused on the issue of IS innovation adoption and provided one theoretical study in IS innovation adoption framework and two empirical studies of organization level Internet-based IS innovation adoption. In the theoretical research, we explored the key determinants of the firm's adoption decision of a specific IS innovation and developed a match-based framework for IS innovation adoption. After our theoretical study, this framework has been tested in two empirical studies both investigating organization level Internet-based IS innovation adoption. In spite of some limitations in these two empirical studies, the results of both our empirical studies provided strong empirical evidences of the applicability of our match-based framework in IS innovation adoption.