The article aims to show evolution of American model of capitalism and its adaptation opportunities to new challenges of 21st Century. The author reviews basic characteristics of American model and its destinction from other market economic models. It is shown that in the USA the leading role in economic development is played by private sector, and the government occupies mush more modest positions. The ideas of independence, self-reliance and individual success definitely prevail both in ideology as well as in economic practices. It is noted that American model underwent several stages in its evolution – from 17th Century until recently and only last period of about 50-60 years may be regarded as a liberal period of economic development. The author demonstrates that because of liberal model the country reached significant economic and social results, including high economic growth and high living standards. The driving force of American model is definitely a private sector of economy, which generates about 90% of GDP and most investments into economy. The liberal model is undoubtfully advantageous for competitive part of society, for efficient workers. The same time it is not a model for a social state, oriented for general welfare. But advantages of American model are quite obvious - it is an orientation for high economic efficiency, for development of science and innovations, for economic growth and high living standards. The shortcomings of American model are also quite evident. Among them is the problem of social and income inequality, the emergence of new economic challenges, including pandemics, climate change which test the American model for its sustainability and effectiveness. One more challenge are new emerging markets which are not liberal at all. Especially we can talk about China which became the real rival to American economy. The modern stage of globalization stands before american capitalism several new problems. Among them is exacerbation of contradictions between old industrial countries and emerging economies, between strengthened multinational corporations and the government of countries they came from. The author makes a conclusion that despite both internal and external challenges the existing potential of American model is still not exhausted. The same time it is evident that the question of its adaption to all existing challenges is quite real and demands its solution.