Abstract: Objective To investigate the acute toxicity of metal exposure on fat storage, and to identify the sensitive genes required for the metabolism of fatty acid in metal exposed nematode Caenorhabditis elegans. Method Silver (Ag), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), manganese (Mn), and zinc (Zn) were chosen as test metals. Nile Red staining was used to evaluate the content of fatty acid in control and metal exposed nematodes. The transcription levels of genes required for fatty acid metabolism were further examined in control and metal exposed nematodes. Results Among the examined metals, exposure to Ag and Cr at the concentrations of 75 and 200 祄ol ?L-1 and exposure to Cu at the concentration of 75 祄ol ?L-1 significantly increased the fat storage, and exposure to Cd at the concentration of 200 祄ol ?L-1 significantly decreased the fat storage in intestine of nematodes. Moreover, exposure to Ag and Cr at the concentration of 200 祄ol ?L-1 did not affect the expression levels of pod-2, gei-7, lbp-8, gpd-3, W05G11.6, C03H5.4 and C07E3.9 compared with control. In contrast to this, the fat-5, fat-6, and fat-7 expression was dramatically increased, and the expression of lbp-1, acs-2 and ech-1 was significantly decreased in 200 祄ol ?L-1 Ag and Cr exposed nematodes compared with control. Conclusion The abnormal fat storage can be observed in nematodes exposed to high levels of Ag, Cr, Cu, and Cd, and the observed formation of increased fat storage in Ag and Cr exposed nematodes was largely due to the abnormalities of fatty acid desaturation, mitochondrial ?oxidation , and fatty acid binding.