This paper attempts to create a systematic approach to combine both law and economics to design antitrust regulations on price announcement behavior of oligopolistic firms. The suggestions made in this paper include: (1) the culpability involved in the case of private price announcement or communication among oligopolistic firms is higher than the public one. (2) the culpability in information dissemination through "real price" is higher than through "list price" announcement; (3) the culpability in exchanges of non-binding future prices among firms is higher than the binding one.