Cloud computing is a new discussion in enterprise IT. It has already become popular in terms of distributed technology in some companies. It enables managers to setup and run the intended businesses by avoiding excessive spending on computers, software and hiring expert staff, which proves to be cost effective. Cloud computing also helps users pay for the IT services without spending massive amounts for integration, maintenance or management of the IT infrastructure. In this paper, we have tried to present a model for evaluating user’s satisfaction in cloud computing. Therefore, a conceptual model has been constructed considering attributes such as (security, efficiency and performance, adaptability, and cost) to evaluate cloud computing users satisfaction in an Internet Service Provider (ISP) companies in Iran. To avoid any ambiguities which are caused by linguistic methods, in this evaluation model we have used Fuzzy Inference System (FIS).