In the conditions of the formation of a market economy in Ukraine, a significant role is given to the development of entrepreneurship as the driving force for the intensification of the activities of economic entities. An analysis of the current state and tendencies in entrepreneurship development of Ukraine was carried out taking into account the criteria for the division of enterprises into micro, small, medium-sized and large in conformity with the legislation of Ukraine. The information base of the research was statistics published on the website of the State Statistics Service of Ukraine for the period 2010-2019. The article describes the dynamics for 2010-2019 of such indicators of efficiency of large, medium and small (including micro) enterprises of Ukraine: level of profitability (unprofitability) of operational activity of enterprises; level of profitability (unprofitability) of all activities of enterprises; proportion of enterprises that received net profit; structure of distribution of capital investments; number of enterprises; volume of sold products (goods, services) of enterprises. The structural distribution of indicators of efficiency of Ukrainian enterprises by type of economic activity for 2019 is displayed. With the help of econometric modeling of dynamics of the number of enterprises, volumes of capital investment and sold products of Ukrainian enterprises for 2010-2019, a trend equation (polynominal type) is built. Summarizing the results of researches, Ukrainian enterprises were divided into large, medium, small and micro enterprises by the value of performance indicators during 2010-2019. To characterize the level of riskiness of activities for each category of enterprises, variation coefficients for the performance indicators of Ukrainian enterprises for the period 2010-2019 were computed. The advantages and disadvantages of organization and functioning of enterprises of different categories are systematized. For the balanced development of the market economy, the need for cooperation and the formation of an efficient mechanism for interaction of all forms of entrepreneurship – small, medium and large, each of which has its own advantages and disadvantages, is substantiated.