Business law is a set of private and public norms belonging to different branches of Polish law. The influence of the Constitution on its development is significant when one takes into consideration the necessary transformation of the economic system linked to the integration within the European Union and the need to modernize many normative solutions accordingly to the progressing changes in economic life. It is of great importance to make constitutional the principles of the economic system called 'social market economy' which has been based on, related to the idea of subsidiarity, principles of economic liberty, protection of property, democratic state of law and equality before the law. The boundaries of the implementation of these principles are determined not only by the norms expressed directly in the Constitution but also directives ensuing indirectly from it, made by deduction. They are apparent in the current economic legislation and its control, in court and official interpretation of the provisions and the whole of the doctrine. The possibility to implement Constitution directly in economic relations is the evidence of the supremacy of its juridical functions over the by programme ideological ones. The constitutional direction for the interpretation of business law has significant meaning in practice leading to additional permeation of constitutional values into this area of regulation in the process of its implementation particularly while determining the meaning of vague provisions, numerous general clauses and poorly defined expressions..