In recent years Cloud Computing has been one of the most discussed references in the world of information technology. As the adoption of Cloud Computing has become so important for firms, a question arises: what is the factor determining the adoption of technology? Thus, the aim of this study is to identify a set of determinants of adoption of Cloud Computing by firms. To reach this goal we suggested a research model based on two theories held in the literature: the diffusion of innovation (DOI) model and the technology organization environment (TOE) framework. To support the suggested model a quiz is even proposed to test the suggested hypotheses. The implications of the results of this study are discussed, both for researchers and for managers. We present the plan to the empirical testing and model validation of the hypotheses suggested. Future extensions to this study are also considered in this paper.