THE PURPOSE OF THIS RESEARCH IS INVESTIGATION THE IMPACT OF TAX AGGRESSIVENESS ON ACCRUALS QUALITY. ACCRUALS QUALITY IS MEASURED BASED ON THE INVERSE CRITERIA OF ABSOLUTE DISCRETIONARY ACCRUALS EXTRACTED FROM THE MODEL PRESENTED BY DECHOW ET AL (1995). ALSO, TAX AGGRESSIVENESS IS ASSESSED BASED ON THE PATTERN PROPOSED BY BALAKRISHNAN ET AL (2014). THE RESEARCH OBSERVATIONS INCLUDED 202 FIRMS LISTED IN TEHRAN SECURITIES & EXCHANGE OVER THE PERIOD 2011 TO 2016. THE RESEARCH HYPOTHESIS ANALYZE BASED ON MULTIVARIATE REGRESSION MODEL USING PANEL DATA AND FIXED EFFECT METHOD. RESEARCH FINDINGS INDICATED THAT TAX AGGRESSIVENESS HAS SIGNIFICANT AND NEGATIVE IMPACT ON ACCRUALS QUALITY. OTHER RESULTS SHOWED THAT FIRM SIZE, LEVERAGE, AGE, GROWTH, LOSS, SALES VOLATILITY AND INSTITUTIONAL OWNERSHIP ARE THE EFFCTING FACTORS ON ACCRUALS QUALITY SIGNIFICANTLY; BUT ACCRUALS QUALITY IS NOT A SIGNIFICANT FUNCTION OF AUDITOR SIZE.