The subject matter of the article is the theoretical and practical aspects of growth, expansion, and functioning of the transnational corporations against the backdrop of the modern transnationalization of the economy. The aim of the work is to research the transnationalization of the economy and to identify the main factors of growth and development of modern transnational corporations. The following tasks were solved in the article: analysis of the level of transnationalization of the economy; definition of modern geographical diversification of TNCs; research the theoretical foundations of corporate growth; creation of practical evidence of a theoretical basis on modern databases; analysis of the influence of the elements of the expansion of TNCs on their profitability. The following methods are used: the graphic method, the statistical method, the comparative method, the index method. The following results were obtained: the level of transnationalization of the world economy in dynamics over the past years has been revealed, which is characterized by a stagnant situation from 2014. The study of the transnationalization of individual economies shows a certain approach of the leaders to the more similar indicators. This trend demonstrates the importance of geographical diversification for TNCs. The relationship between the profit and the using of various specific expenses was discovered. It has been revealed that R & D, as a component cannot independently provide the sufficient competitive advantages to the ever-growing technological solution of global competitors. The need for the existence of specific capabilities of the company due to the proper management in the geographical structure is confirmed. It is noted about the change in the local position of both the parent companies and affiliates of TNCs, which leads to transnational competition between countries. The need of simultaneous use of multiple methods of growth is noted. Conclusions: the studied at the work theoretical and practical aspects demonstrate the importance of each element of the TNCs. The expenses of corporations are necessary for the development and expansion of activities. Marketing costs, migration force, R & D costs, geographic diversification management make it possible to use the potential of companies more widely while simultaneously using different methods. Practical consideration has allowed to determine that the maximum result is achieved by a combination of several elements of growth, thereby creating so-called "profitable giants".