The purpose of this study is to explain the relationship between variables of organizational climate, organizational commitment, job involvement and organizational citizenship behavior. The study population included 1276 employees of the gas company in Khuzestan province. To this aim 296 subjects were selected according to the Cochran formula. To collect data, questionnaires of OCB of Podsakoff et al (1990), organizational commitment of Allen and Meyer (2010), job involvement of Edward Zuchil Patrick (1984) and the organizational climate of Halpin and Craft were used. To analyze the data, Lisrel 8.80 and spss16 were used and results of structural equations and Pearson correlation coefficients indicated that there is a statistically significant relationship between organizational climate and organizational commitment, between organizational commitment and job involvement, between job involvement and organizational citizenship behavior, between organizational citizenship behavior and organizational climate and job involvement.