Gelfond and Lifschitz introduce a declarative language A for describing effects of actions and define a translation of theories in this language into extended logic programs(ELP, s). The purpose of this paper is to extend the language and the translation to allow reasoning about the effects of concurrent actions. Logic programming formalization of situation calculus with concurrent actions presented in the paper can be of independent interest and may serve as a test bed for the investigation of various transformations and logic programming inference mechanisms.