Abstarct: For the past couple of decades, numerous engineers and researchers has been working on the effects of masonry infilled walls in concrete frxames. Also the effects of infill walls on the behavior of structures has always been an important issue for structural engineers. Since the quality of materials and their strength and stiffness are related to the quality of materials and their availability, most countries have set specific rules in their codes for effects of masonry infill walls. Also, our country, IRAN, has done the same thing and for the past few years, we have seen some of these changes in Iranian seismic code. In article 1-5-6, for example, the effect of masonry infill walls in building behavior is noted. According to this article if non-structural elements prevent the lateral movements of the structure, we must consider the interaction between these elements and structural elements in analysis. In Iran, due to lack of adequate knowledge about behavior of masonry infill walls engineers are not interested in modeling the masonry infill walls and as result they ignore the positive and negative effects of masonry infill walls on the behavior of structures. The objective of this study is to determine the requirement parameters of the R factor of infilled frxames. Some of these requirement are as follows: - Surveying the interaction between masonry infill walls and concrete columns - The effect of masonry infill walls on the period of concrete structures. - The effect of masonry infill walls on strength and initial stiffness of structures - Distribution of forces in elastic and plastic modesbetween masonry infill walls and concrete frxames. - The effect of masonry infill walls on lateral displacement (drift) In this study by using a nonlinear static analysis (pushover) interaction between concrete frxame and masonry infill walls and also effects of masonry infill walls on the period of concrete structures and lateral drift has been determined.