To investigate the protective effect of purple sweet potato flavonoids (PSPF) on CCl4-induced acute liver injury in mice. Sixty mice were randomly divided into six groups (n=10 in each): blank group, model group, PSPF groups (400 mg*kg(-1), 200 mg*kg-1 and 100 mg*kg(-1)) and positive control group (DDB 150 mg*kg(-1)). Acute liver injury was induced by administration of peanut oil with 0.1% CCl4 (10 mg*kg(-1)) in mice. The viscera index, serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were measured, and the activities of superoxide dismutase (SOD) and the contents of malondialdehyde (MDA) in hepatic tissues were also measured. The pathological changes of liver were observed with microscopy. PSPF significantly decreased serum ALT, AST and LDH levels (P<0.05 or P<0.01) and MDA content in hepatic tissues (P<0.01), increased the activities of SOD (P<0.01). Purple sweet potato total flavonoids can prevent CCl4-induced acute liver injury in mice, which may be related to inhibition of lipid peroxidation and reduction of oxygen free radicals.