Background: Explaining the role of tax morale in the relationship between social capital and tax compliance is the most important research area. Because, there are many evidences showing that the decision to pay the taxes to be influenced by factors other than mentioned in the economics of crime approach. The main goal of this research is to investigate the mediator role of tax morale in the relationship between social capital and tax compliance.

Method: This is an applied research in terms of aim and descriptive-correlation in terms of data collection. Research population consists
of 715 tax payers in fraternity of home appliances and jewelers that 163 of them were selected through random sampling. Data were collected through questionnaire. Structural equation modeling was used to analyze the data through LISREL and SPSS software.

Results: Results show social capital with standardized coefficient of 0.49 and significance of 5.03 had positive effect on tax morale. Also, tax morale had positive effect on tax compliance with standardized coefficient of 0.86 and significance of 6.16

Conclusion: The present study confirmed the significant effect of social capital on tax compliance and mediator role of tax morale between their relationships.