In article on the basis of the analysis of works of the Russian and foreign scientists-lawyers, experts lawyers, and also economists the contract research as economical and legal design is conducted. The contract as an economical and legal design represents the special economical and legal mechanism regulator mediating economic activity, designed to provide legal satisfaction of economic interests, certain subjects, formed by the elements interconnected and coordinated among them.It is revealed that such economical and legal design consists both from legal, and from economic elements. It is formed of the following obligatory and necessary elements: (1) legal procedure of coordination of terms of the contract, (2) form of the contract, (3) term, (4) subjective rights and legal obligations of the parties, (5) valid economic contents of the contract. The list of the designated elements of the contract is open and depends on complexity of the most economical and legal design and a type of the bilateral or multilateral civil transaction.The nature of its legal communications exerts impact on an economical and legal orientation of a design of the contract. In turn features of contractual communications affect achievement of the legal purposes.It is proved that the contract as an economical and legal design has to be always filled with economic sense. It is shown that lack of the valid economic sense of the contract is considered by law-enforcement practice therefore leads to adverse legal effects.