Objective To investigate the liver injury mechanism induced by D-galactose and L-glutamic acid in tree shrews. Methods Male tree shrews were randomly divided into four groups: the control (CT), D-galactose (D), L-glutamic acid (G) and D-galactose combined with L-glutamic acid (D+G) groups. The weight and survival rates were recorded weekly. Medication was administered for 8 weeks, then the tree shrews were sacrificed. Their livers were perfused with 4% paraformaldehyde for hematoxylin and eosin and immunohistochemical staining to detect TLR2, NF-κB and P- glycoprotein (P-gp) expressions. Results The body weights in the D+G group were lower at week 8 than at week 1. The survival rates in the G, D and D+G groups decreased compared with that of the CT group. Hepatocytic degeneration, edema, necrosis and inflammatory cell infiltration occurred in addition to dilatation of the central and portal vein and the branch bile duct in the livers of the G, D and D+G groups. Compared with CT group, the expressions of TLR2 ( P < 0. 05), NF-κB (P < 0. 01) and P-gp (P< 0. 01) were significantly increased in the D, G and D+G groups and were significantly higher in the D+G group than in the D or G groups. Conclusions D-galactose and / or L-glutamic acid induce liver tissue injury in tree shrews, which may be involved in activating TLR2 / NF-κB signaling and P-gp.