In introduction the author specifies importance of the innovation introduced by the new civil code, this innovation is the conjugal contract. The purpose of his article is to fill, at least partially the emptiness existing in this sphere and to acquaint the readers with the usual for today situation in the modern right, in connection to the conjugal contract of the spouses, participating in commercial communities such as companies. The first part of article is dedicated to consideration of the specified question concerning organization of the solidary responsibility; in the second part in is considered the problem of participation of the spouses in a commandant community. In the end the author comes to the appropriate conclusion and once again emphasizes special importance of the conjugal contract in connection to the above-stated question.