In this paper, a three-dimensional, three-phase model of cyclic steam injection to the heavy oil reservoir is used. Evaluation studies of cyclic steam injection in the heavy oil reservoir (in Iran) show that the important roles of steam injection rate and steam injection period and the role of the soaking period is not noticeable. It is shown although increasing steam injection rate and/or steam injection period increases oil recovery but increasing steam injection rate and/or increasing steam injection period is not economical.