The survey is aimed to justify system approach to assess companies’ interaction and environment in tourism clusters. Intangibility of tourism product is determined by the specifics of economic entity and territorial authorities’ interaction, that makes it a prerequisite to use system approach for companies’ interaction within regional tourism cluster. The paper identifies institutional environment of business development in tourism cluster taking into accountthe rapid development of communication and information technologies. To achieve this goal the authors analysed the theoretical frameworks of institutional environment of tourism and the process of its formation and factors. The proposed technique is based on system approach and allows to indicate the deficiency in tourism cluster models, taking such critical issues into account as interconnection between cluster actors, regional competition policy, investment climate, development of standards and systems for the services certification, availability of qualified personnel in the region’s labour market, tourism infrastructure, financial and tax policies in the region, network of competitive local suppliers, public policies on tourism, tourism support programs and communication problems. As a result, the rationale of using system approach to evaluate effectiveness of subjects’ interaction in tourism clusters to determine weaknesses in regional tourism clusters was formed