The article is devoted to the results of the research of small business development in Russia and Poland for 10 years. The data comes from the reports published by Polish Agency for Enterprise Development and the Russian SME Resource Centre (RCSME). The author analyzed the following indicators: the number of active SMEs, the amount of employees in SMEs and their contribution to Gross Domestic Product (GDP) both in Russian Federation and Republic of Poland. The concept of the ecosystem in terms of studying the changing processes considered in the article. SMEs have a key role in these processes. Recommendations for small and medium entrepreneurship development are given at the end of the article.