The Purpose of this research is to be traced the internalization process of the tourism business over the last decades in our country. It has been reasoned by a number of foreign economic factors by virtue of the open character of our national economy, the course of the transition economy reforms, as well as the peculiarities of the Bulgarian economy EU integration. The relation "internationalization of business - internationalization of the national economy" is studied in different directions and methodology, but in the present study an adapted version of the method developed by Alan Rugman is applied. The main approach is based on the comparison between the degree of internationalization in the national economy and the degree of internationalization of a specific type of business. The measurement of the degree of internationalization is done with the help of variables and a system of indicators, which are directed respectively to the business environment of the Bulgarian economy and to the specifics of the Bulgarian tourism business. As analysis findings of the processes of internationalization in the context of tourism, it is concluded that these processes play an important role in determining the position of Bulgarian tourism in its inevitable competitive opposition to other tourist destinations and their business. As limitation have been identified two periods of research on the degree of internationalization of business - the first covers seven years before Bulgaria's accession to the EU, and the second period - almost ten years after the signing of the membership agreement. The practical implication of the study consists in the fact that the effect of the increasing degree of internationalization of the tourism business in our country complements the overall result of the internationalization of the Bulgarian economy. This is especially clear in the second observed period of the study, which is expected to achieve a general synergy effect for the economy as a whole. The originality of the research consists in the adaptation as well as approbation of a known methodology for studying the processes of internationalization to the specifics of tourism business and to a given economy, such as the Bulgarian one, for two separate periods.