Self-Determination Theory as a Framework for Exploring the Impact of work Climate and Social network size on Motivation of Volunteering activities

In the present study, Through the application of self-determination theory the impact of work climate and social network size on the volunteers motivation were investigated. research type of this study is applied and research method type is Descriptive. In this study Active volunteers of Tehran Red Crescent Society were selected as Statistical population .Concerning the population of studied center, sample size was estimated 146 by Cochran Formula. The sampling process was done by two stage Cluster sampling method . To complete available data, standard questionnaires were used. To test hypotheses, Structural Equation Modeling (SEM)using LISREL software were employed. The results showed that the work climate has positive impact on the volunteers autonomous and controlled motivation and the needs satisfaction acts as a mediator of both impcts. Also the results showed that the social network size has positive impact on the volunteers autonomous motivation and negative impact on the volunteers controlled motivation and the needs satisfaction acts as a mediator of both impcts.