The article highlights the problematic issues of the novels of legislative regulation of the object, on which implementation of the Prosecutor’s Office of Ukraine function of representation of interests is directed. It has been established that the object of the representation by the Prosecutor’s Office of Ukraine during the implementation of the corresponding function should recognize the public interest as a social interest recognized by the state, as well as the state interest, which is designed to meet the needs of society, not the interests of the state represented by the state bodies. It has been proposed a definition of the legal formula of public interest as indicative list of major legal components which may be present in the public interest.