Objective: To observe the homing of mesenchymal stem cells (MSCs) transfected with adenovirus containing mouse CXCR4 gene to the injured liver. Methods: The mouse MSCs were isolated, expanded in vitro and then identified. The target CXCR4 gene was obtained from mouse liver, and the adenovirus vector Ad-mCXCR4 was constructed by homologous recombination and identified. MSCs were transfected with Ad-mCXCR4, with the MSCs transfected with empty vector Ad-vector or without transfection serving as controls, and the CXCR4 protein expression in each cell group was determined by Western blot analysis. Mice were randomly divided into three groups after the establishment of CCl4-induced liver damage, and then, the Ad-mCXCR4 transfected MSCs, Ad-vector transfected MSCs or non-transfected MSCs were injected into the mice through tail vein, respectively. At 48 h after injection, the MSCs homing signals from the injured liver tissues of each group were detected by laser confocal microscopy. Results: Recombinant adenovirus vector Ad-mCXCR4 was constructed successfully. The MSCs transfected with Ad-mCXCR4 presented a strong CXCR4 expression, while the MSCs transfected with Ad-vector or without transfection had no CXCR4 expression. No green fluorescent protein-positive cells were noted in the liver of mice injected with non-transfected MSCs, and the number of green fluorescent protein-positive cells in the liver of mice injected with Ad-mCXCR4-MSCs was significantly higher than that of mice injected with Ad-vector-MSCs [(21.25±1.56) vs. (5.42±0.81)] (P<0.01). Conclusion: CXCR4 expression can be elevated in MSCs by gene modification technique and the homing of CXCR4-overexpressing MSCs to the injured liver is enhanced.