Abstarct: The stock market has a special role in the efficiency of the financial and economic system of a country, and by attracting, directing and allocating the funds available in the society, towards making investments in the production and service sectors, it causes the prosperity of industries, job creation, and exit from the economic crises. Individual investors play an important and vital role in the stock market due to having adequate savings, therefore, it is very important to not only investigate and identify the factors affecting their decision to invest, but also to identify the behavioral pattern of these people. baxsed on the mentioned topics, this research intends to perform analysis and mining the behavior pattern of investors in the stock market by using rough set theory, considering behavioral factors and characteristics, and baxsed on verbal and non-verbal criteria approach. This study is a descxriptive type research (in terms of collecting information and examining influencing factors), a fundamental type research (baxsed on the purpose, and in terms of extracting the basic behavioral pattern), and an applied type research (in terms of the goals of using and the fields of use of the extracted pattern). In this regard, 400 samples of individual investors were selected and examined and the essential analyzes were performed using Excel, SPSS Modeler and Rosetta software, and finally 3 rules including the most supports have been selected to further investigating. Accordingly, and baxsed on the research results, the behavior pattern of investors has been mined and extracted. Moreover, the results show that cognitive biases with 6 behavioral characteristics, emotional biases with 5 characteristics, and cultural biases with 1 behavioral characteristic have the greatest impact on people's investment decisions. In addition, the extracted behavioral pattern has been compared with the results of other related sources and references, and by conducting a risk assessment test and receiving people's preferences in forming stock portfolios considering various stock exchange industries; the validation of the research results and the extracted behavioral pattern has been checked. The results show the high degree of validity and reliability of the extracted behavioral pattern.