Abstract: To detect therapeutical and preventative effect of β-carotene on hepatic fibrosis in KM mice induced by repeatedly administered concanavalin A.90 KM mice were divided into four groups: normal control group (n=10) , uninterfere group which were injected weekly with ConA (n=10) , prevention group which were intragastric administrated with β-carotene, as injecting ConA (n=10) , treatment group (n=50) , and placebo group (n=10) .Mice in these first three groups were killed at 9th week.While therapy group were intragastric administrated with β-carotene after 9th week and then were killed in batch at 1, 2, 3, 4, 5 weeks later.Placebo group were intragastric administrated with 9% NS instead and were killed at 14th week.ALT and AST in serum were measured.Liver pathological changes showed that mice in therapy group had been cured in 5 weeks.β-carotene could prevent and treat hepatic fibrosis.