Objective：To observe the effect of 2，3，4’，5-tetrahydroxystilbene-2-O-β-D-glucoside （TSG） on hyperlipidemic fatty liver in rats，and explore the potential mechanisms by PPAR α signaling pathway. Methods：SD rats were randomly divided into control group，model group，TSG 80 mg/kg group，MK886 plus TSG 80 mg/kg group. The rat model was established by orally feeding high-fat emulsion for 4 weeks. Then TSG was administered to these rats for 6 weeks. TC，TG and FFA levels in serum and hepatic tissues，hepatic weight coefficient，the levels of alanine aminotransferase（ALT）and aspartate aminotransferase（AST）in serum were measured；and the hepatic histopathological changes were observed. Meanwhile，the expressions of PPAR α，LC3Ⅰ，LC3Ⅱ，Beclin 1 and p62 proteins in hepatic tissues were measured by Western blot. Results：Compared with the model group，TSG could significantly decrease TC，TG and FFA levels in serum，TG and FFA contents in hepatic tissues，hepatic weight coefficient，and also the serum levels of ALT and AST（P＜0.05 or P＜0.01）. Meanwhile，the histological evaluation of liver specimens revealed that lipid accumulation in TSG-treated group was obviously ameliorated. Western blot results showed that TSG could markedly up-regulated the expressions of hepatic PPAR α，LC3Ⅱ，Beclin 1 proteins，and down-regulated the expression of p62（P＜0.05 or P＜0.01）. However，the effect of TSG was weakened or cancelled when pretreatment with PPAR α antagonist MK886. Conclusion：TSG was effective in treating hyperlipidemic fatty liver in rats，and its mechanism might be related to the up-regulation of LC3Ⅱ and Beclin 1 protein expressions，down-regulation of p62 protein expression to activate autophagy by activation of PPAR α，and eventually to improve lipid metabolism.