Until now, most of the studies about the internet service have focused mainly on the adoption of on-line(wired) internet services, while there have relatively been very few studies about the adoption and usage of wireless or mobile internet services. The generic model explaining the adoption behaviors of wireless internet services has not been made yet. Previous studies of that area is not so easy to find. The purposes of this paper are two-folds. The first is to find the factors affecting the users` intention and commitment behavior of mobile internet services. The second is to find the relative importance of the factors in users making decisions about users` usage intention and commitment behavior. In the theoretical part of this paper, the precedent studies concerning the technology acceptance model and the theories of on-line internet services adoption, the theories of the mobile internet services, are reviewed and analyzed.