The impact of information systems (IS) on organizational performance has gained enormous attention from both academics and practitioners. However, it is the post-acceptance IS use that actually help fully realize the IS potential. We identified three types of IS usage behaviors -- routine use (RU), extended use (EU) and innovative use (IU), which can coexist in the post-acceptance stage and help with the work. Drawing on the IS success model, we proposed a research model with IS characteristics as external variables toward perceived usefulness (PU) and satisfaction to explain RU, EU and IU in respective. The relationships among three dimensions of IS characteristics -- information quality, system quality and service quality were discussed further. As RU, EU and IU reflect various extent of IS use, we suggested that they are linked. Then the model was tested by a survey of 240 ERP system users. The results provided evidence that information quality and service quality influence PU and user satisfaction via system quality, and IS success model was a good basis for understanding RU, EU and IU. We also found that RU had a positive impact directly on EU but indirectly on IU via EU. This study helps bridge the gap between IS characteristics and prediction of different types of post-acceptance IS usage behaviors.