Market disorder and irrational behavior of investors escaiation stock market volatility.. Reviewing the background of the research has shown that a comprehensive model has not been done in the field of legal or institutional investment, but each research has dealt with a part of the subject .This research has been conducted with the purpose of identifying drivers and consequences of behavioral bias and strategies for reducing the effects of bias behavioral in institutional investors with the correlation research method. The evidence collected from a possible statistical sample of 607 legal investors has been analyzed using a questionnaire, using confirmatory factor analysis and structural equation modeling.The results have shown that increasing the causes and bases of bias (factors: social, knowledge and experience, market and psychological) leads to an increase in behavioral biases, the use of behavioral biases strategy in investors' decision making. Also, the strategy to reduce of behavioral biases is influenced by behavioral biases, background factors, and intervening factors. In the end, the success of investors is significantly influenced by the behavioral biases to reduce strategy, the causes of the behavior biases, and the behavioral biases. Evidence has shown that the investigated model has predictive validity for investment performance that institutional investors can benefit from this study by understanding the influence of behavioral factors on investors' decisions.