The filamentous fungus Neurospora crassa is an important model organism for studying genetic regulation, circadian rhythm and light response. This review summarized the structure and functions of WC-1 and VVD, and their participation in regulation of circadian rhythm and photoadaptation. All known light responses in Neurospora are regulated by blue light through two photoreceptors WC-1 and VVD. WC-1 is a transcription factor in this fungus and initiated the light response, generating a lot of light-responded proteins, such as VVD. VVD suppresses the transcription function of WC-1through negative feedback mechanism. In addition, the vvd gene has been applied to construct the photoresponsive elements of various genes in mammalian systems.