Abstract：Objective：To observe the effects of NYGGF4 overexpression on mitochondria in 3T3-L1 adipocyte. Methods：The coding sequence of human NYGGF4 gene was inserted into the pcDNA3.1Myc/His B vector to become recombinant expression plasmid NYGGF4-pcDNA3.1/myc-His B which was subsequently transferred into 3T3-L1 pre-adipocyte. The transfected 3T3-L1 cell expressing NYGGF4 was selected with neomycin (G418), and identified by RT-PCR and western blot. The effect of NYGGF4 overexpression on mitochondrial morphology in transfected 3T3-L1 was evaluated by transmission electron microscope. The levels of peroxisome proliferatoractived receptor co-activator 1α (PG1-α), nuclear respiratory factor 1(NRF1) and mitochondrial transcription factor A (mtTFA) mRNA in the transfected 3T3-L1 and control cells were detected by realtime quantitative RT-PCR. Results：RT-PCR and western blot demonstrated that the 3T3-L1 strain stably overexpressing NYGGF4 was established successfully. The overexpression of NYGGF4 may lead to abnormal mitochondrial morphology and increased PGC1-α mRNA level in adipocytes but no increased NRF1 andmtTFA mRNA was found. Conclusions：The overexpression ofNYGGF4 may damage mitochondia in adipocytes.