The invention relates to the technical field of medicaments and discloses the novel application of a penthorum chinense pursh extract or compounds of ursolic acid, pinocembrin, scopoletin, gallic acid, ursolic acid-28-xylose-(1-3)-glucoside, pinocembrin-7-glucoside, pinocembrin-7-neohesperidoside, scopolin or galloyl glucoside separated from the penthorum chinense pursh extract. Pharmacological and pharmacodynamic tests show that the penthorum chinense pursh extract or the compounds can obviously reduce the rising of aspartate aminotransferase (AST), glutamic-pyruvic transaminase (ALT) and alkaline phosphatase (ALP), caused by acute liver injury, alcoholic liver and virus hepatitis in mice, chronic hepatic fibrosis in rats and the like, has an obvious inhabitation effect on HepG2 tumor cells and can reduce the cholesterol and triglycercide content of blood serum. The penthorum chinense pursh extract or the compounds are simple in preparation method and low in cost. The invention provides a new medicament source for preventing and treating hepatitides, liver injury, hepatic fibrosis, cirrhosis, alcoholic liver, liver cancer and diseases associated with high blood fat.