The article shows analysis of the main indicators of the development of small and mediumsized enterprises, conclusions about structural disproportions. At the same time, emphasis is placed on moving to mediumsized businesses, which is impossible without the integration of large and small businesses based on specialization and co-operation of capital with maximum use of each. In the article were used methods of economic analysis: comparisons, groupings, structural and logical analysis, systematization and generalization. The results of the paper: the identified main trends in the development of small and medium-sized businesses, sectoral disproportions related to the development of the small and medium-sized business sector in the sectoral context; an analysis of the development of technoparks and industrial clusters in Kazakhstan; the identified proposals on the intensification of the processes of production specialization and cooperation of small and largeenterprises. The results may be used as a scientific support in the development of activities for the development of the small and medium business sector. The paper is aimed at attracting the attention of entrepreneurs with the aim of activating the integration of small and large enterprises, creating favorable conditions for the transition of small businesses to the middle on the basis of specialization and cooperation.