The present invention relates to a pharmaceutical composition containing a G protein coupled receptor 119 (GPR119) ligand as an active ingredient for preventing or treating non-alcoholic fatty liver disease. More particularly, it was confirmed that the GPR119 ligand, which has been developed as only an anti-diabetic drug, exhibits superior effects on the treatment of non-alcoholic fatty liver and the signal pathways in hepatocytes therefor differ from the signal pathways in the small intestine and the pancreas exhibiting anti-diabetic effects, whereby the GPR119 ligand can be useful to treat non-alcoholic fatty liver.