This paper considers how constructive and functional approaches to studying entrepreneurship can be applied in accordance with interdisciplinary methodology. It discusses problems of identification of entrepreneurs - identification and systematization of the executable of their professional functions due to the target goals of business's role in life and which form the content of entrepreneur-ship as one of areas of human activity. The author draws attention to the need to systematize entrepreneurial functions, which form the core of the identity of the entrepreneurial profession and forms its unique functional specificity, which distinguishes it from the professions of manager, engineer, inventor, designer, economist, and other professions that have their own functional specificity. The article also considers the question of correlation of the core identity of entrepreneurial profession with entrepreneurial functions and personality traits of entrepreneurs. Namely, it is described the structure of blocks of personal traits of entrepreneurs necessary for them to conduct successful entrepreneurial activity. The author concludes that the application of the functional approach would make it possible to successfully advance in solving the scientific problem of substantiating the irreducible identification core of the system of theoretical entrepreneurship concepts, its evolution, as well as to achieve an orderly application of the «entrepreneurial» terminology in theory and practice.