The main objects of this diploma thesis are basic trends in the mortgage market in the United States and their role in the current mortgage crisis. As a theoretical background in the first part of this work are mentioned asymetric information with the optimal consumer choice regarding mortgage product and the general theory of the securitization. Practical part continues from the description of the main characteristics of the mortgage to the whole mortgage market and the role of government agencies. Following analysis is concerning the significant tendencies in the past years, which dominates in the mortgage market in the USA. The focus is mainly aimed at the growth of alternative mortgage products in connection with strong home price aprec...