Gains promised by the introduction of e-commerce back-office systems are not easily realized due to poor technology acceptance, especially in developing countries. This study aims to analyze factors which affect information technology acceptance in developing countries. A research model based on TAM is proposed, and it is empirically tested for the hypotheses of factors which affect the acceptance behavior. The result shows that antecedents such as user training influence the technology acceptance in different ways. This study may help accelerate the adoption of back-office systems in developing countries.