Objectives: By Social capital we mean a network of inter-personal and inter-group relationships and ties based on social trust. Such a network also includes interactions of individuals with groups and social institutions which enjoy solidarity and collective cohesion, and within which individuals and groups maintain social support and the necessary energy. These qualities are required in order to facilitate actions oriented toward achieving personal and collective objectives, The above description summarizes the main subject of this paper. Iran is a society in transition, a society which faces the declinc of social capital and its negative consequences. The erosion, or decline, of social capital in Iran, and its accompanying negative consequences necessitate an attempt geared toward portraying a possible future perspective of it, and also of studying the feasibility of transition from status quo to a desirable situation. Method: This paper initially reviews the existing theoretical approaches and empirical sources pertaining to social capital. Then, social capital is discussed as a complex and multi-dimensional concept within an integrative conceptual framework which is related to an interrelated set of macro, med, and micro variables. It then introduces a multidimensional scale for measurement of social capital. This scale is provided with the necessary requirements of validity and reliability. The statistical society consists of inhabitants of 15 years of age and above, residing in centers of 30 provinces of the country out of which 12000 persons were selected through multistage cluster sampling method. The questionnaire has been the main data collection technique in this research. Data analysis has been conducted through simple and complex qualitative and quantitative techniques. Findings: Given the components included in the five-dimensional measurement scale, quality and quantity of social capital, particularly at thc associative network level, is low Thc dominant type of social capital is of an in-group and the old one, and its implications in terms of human and social development, including universalism and universal collective cohesion are low. But at a micro level, such as feelings of health, success satisfaction and joyfulness its rating is relatively high. Results: The current state of social capital in Iran is low in rating, the old type is dominant over the new one, and there is a negative role the dominant type plays in hindering the formation of social solidarity at the national level. Therefore, it seems necessary to reinforce the new type of social capital specially in the dimension of associative ties and the positive outcomes which these ties provide via modification and improvement of the social milieu and of individual and collective actors, the strengthening of civil institutions, and in reform it brings about through modifying and broadening the individuals’ attitudes and patterns of their actions.