Early days, the prevalence of Internet technology generated e-commerce, e-business, and innovative products and services to market. At present, the diffusion of mobile technology creates m-commerce. Mobile banking is a banking service which helps customers in easily making online transactions anywhere, anytime. It has been adopted extensively in developed countries. However, for Thailand, this acceptance rate is still low. Thus, this paper is aimed at to gather factors affecting m-banking acceptance, both on adoption side and barrier side, to explore the effects of those factors, to guide banks and financial firms to attract more customers, and to compare the differences and similarities of m-banking key success factors from different countries. The quantitative approach using questionnaire survey along with the qualitative approach using interviews are used to test the model. The result shows that the positive factors have more influence on an intention to use m-banking than the negative factors.