NOR1 is a novel nasopharyngeal carcinoma(NPC) associated gene. It is significantly down-regulated in NPC cell line HNE1 and spontaneous NPC biopsies. Over-expression of NOR1 in HNE1 cell line is effective to inhibit HNE1 cell growth and proliferation. To establish a clearer picture of what the functions of NOR1 might be and to identify cellular proteins that might bind to NOR1, a yeast two-hybrid screen was performed to search for proteins that interact with NOR1. 10 positive clones which encoded for 7 polypeptides were successfully isolated. Among these 7 candidate interaction proteins, one candidate was mitochondria ATP synthase subunit OSCP. NPC cell line 5-8F cells were transfected with pCMV-myc-NOR1 plasmids, then the mitochondrial proteins and cytoplasmic protein were isolated by cellular subftration and subjected to Western blot assay. The data showed that myc-NOR1 protein distributes in mitochondrion and cytoplasm. Immunofluoresence assay also showed the endogenous NOR1 protein co-localized with mitochondrion in human normal nasopharyngeal epithelial cells NP69, which indicate that NOR1 is a novel mitochondrial protein. The interaction between NOR1 and OSCP was confirmed by specific yeast two-hybrid assay, immunofluoresence co-localization and co-immunoprecipitation assay. These primary work suggests NOR1 may be involved in energe metabolism.