At present, commercial refined chicken fat and chicken protein hydrolysates are usually used as raw materials for the industrialized production of Maillard reaction chicken flavor. However, commercial refined chicken fat contains a large amount of anti-oxidant, which is hard to be oxidized by low-temperature heating. It is easy to produce off-flavor for chicken fat when heated at high temperature. In order to form enough chicken flavor precursors for Maillard reaction chicken flavor preparing, we studied the mild thermal oxidation of refined chicken fat based on enzymatic hydrolysis, which was with the lipolytic ratio, fatty and greasy taste as evaluation indexes. Under the conditions that the substrate concentration of chicken fat was 30%, pH was 8.0 and temperature was 40 ℃, 60 U lipases were added per 1 gram of chicken fat and reaction time was 6 hours, the lipolytic ratio was up to 45.18%, which were the optimum conditions for the mild thermal oxidation of chicken fat. Compared with the natural chicken broth, GC-MS-O showed that the flavor made by refined chicken fat appeared less characteristic chicken meaty and fatty, and the one made by high temperature oxidation of chicken fat had obvious off-flavor. Moreover, the flavor from enzymatic hydrolysis-mild thermal oxidation of chicken fat showed the highest degree of similarity.