C/EBPs are a group of heat-stable transcription factors which function extensively. They not only involved in normal process of physiological metabolism but also are related to the occurrence and development of many kinds of disorders. C/EBPs have multiple modes in which they act as activator or inhibitor in regulating transcription. All these various functions of C/EBPs are related to their special structures that characterize the members of bZIP family.With themselves or other isoforms, C/EBPs can form homodimers or heterodimers that contain different regulational informations.Furthermore, they can interfere with a wide variety of protein factors, thus the mode and specificity of the functions of C/EBPs are determined.