【Objective】To investigate the mesenchymal stem cells（MSC）in treating acute lung injury（ALI）via ALI mouse model.【Methods】By monoclonal antibody Anti-GD2 of specific antigen ganglioside（GD2）only expressed on MSC as a carrier， new fluorescent molecule probe were synthesized through covalently coupling Anti-GD2 and fluorescent group CyDye mono-reac? tive NHS Esters（Cy7）. Synthetic Anti-GD2-Cy7 and MSC were labeled by the specific binding of antigen and antibody in vitro. Total 84 balb/c male mice were selected and randomly selected 48 mice were divided into three groups：sham group（n = 16），MSC+ ALI group（n = 16），NS + ALI group（n = 16）. The lung histopathology and scores，lung W/D ratio and permeability of lung microvas? culature were examined at 24 h，48 h after ALI mouse model. Other 36 mice were randomly divided into three groups：normal group （n = 12），sham group（n = 12），MSC + ALI group（n = 12）. Labeled MSC-GD2-Cy7 were transplanted into MSC+ALI group and sham group mice via tail vein injection. At 30 min，1 d，3 d，and 7 d post-MSC-GD2-Cy7 injection，the mice were sacrificed after anesthesia and then the lung was removed. Excised lung was detected on small animal fluorescent imager.【Results】Contrast to NS+ ALI group，the lung histopathology and scores，lung W/D ratio and permeability of lung microvasculature of MSC + ALI group weremore greatly improved at both 24 h and 48 h. Fluorescent results showed that the signal intensity in the lung of MSC + ALI group was significantly higher than that of sham group at each time point［（3.37 ± 0.02）× 10 -4 vs（2.05 ± 0.04）× 10 -4 scaled counts/s；（35.54 ± 0.47）× 10 -4 vs（25.29 ± 1.48）× 10 -4 scaled counts/s；（11.17 ± 0.75）×10 -4 vs（6.09 ± 0.62）× 10 -4 scaled counts/s；（3.10 ± 0.14）vs （0.00 ± 0.00）× 10 -4 scaled counts/s；all P < 0.05］.【Conclusion】Our study showed that a proportion of cells migrated into normal and injured lungs 30 min after cell transplantation，and the cells started to recruit and largely gather in injured lungs at day 1 and per? sisted to day 7，these results suggest that MSC possess the ability to home into injured tissues.