Objectives: The purpose of the present study is to answer the key question whether study approach and learning style are related to students' critical thinking level? Method: The statistical population of this study consisted of the students of Islamic Azad University of Guilan in the academic year of 96-97. Based on Cochran's restricted society formula, 386 people were studied using non-probability sampling method. A standard questionnaire was used for data collection. In order to ensure content validity, professors were used collectively and necessary modifications were considered. Internal consistency and Cranach's alpha test were used to assess the reliability of the questionnaire. Data were analyzed using KolmogorovSmirnov test, x2, confirmatory factor analysis, and structural equation modeling which were performed by SPSS25 and Amos24 software. Results: According to the results and the level of significance, it was found that learning style has a significant effect on critical thinking, and also on the results and the level of significance it was found that the study style has a significant effect on critical thinking. Conclusion: Learning is the result of the planned or experiential training that is institutionalized through continuous practice or encounter in the individual and manifested in external behaviors, based on different schools of learning, learning at any time and place and in any subject matter, skill. It requires certain things. Therefore, 21st Century Learning Skills Experts have a set of skills such as critical thinking, information technology, effective and interactive communication, creativity and risk taking, interpersonal skills, personal, social and civic responsibility, high productivity, Priority, planning and management know flexibility and adaptability and confidence.