The present study was conducted with the aim of investigating the relationship between dynamic capabilities and competitive performance of the company with the role of mediator of open innovation in knowledge-based companies in Mazandaran province. This study is applied in terms of purpose and descriptive-correlational in terms of method. The statistical population of the study consists of all knowledge-based companies active in Mazandaran province, and the unit of analysis in this study is managers and experts aware of the strategic, innovative and functional status of the companies. The data collection tool was a standard questionnaire, whose validity was confirmed through content validity and construct validity, and its reliability was confirmed using Cronbach's alpha and composite reliability. Descriptive and inferential statistics were used to analyze the data, and structural equation modeling was used to test the research hypotheses and examine the relationships between variables with the partial least squares approach using SmartPLS software. The findings of the study showed that dynamic capabilities have a positive and significant effect on open innovation and the competitive performance of the company. Also, open innovation has a positive and significant effect on the competitive performance of knowledge-based companies. The results also indicate that open innovation plays a significant mediating role in the relationship between dynamic capabilities and the competitive performance of the company; meaning that companies with higher dynamic capabilities can improve their competitive performance by developing and strengthening open innovation. Overall, the results of this study emphasize the importance of simultaneously paying attention to dynamic capabilities and open innovation as two key factors in improving the competitive performance of knowledge-based companies and can be an effective guide for managers of these companies to increase flexibility, take advantage of environmental opportunities, and strengthen competitive advantage.