The bronze mou as an important bronze artifact was commonly used in Ba-Shu region (now in Chongqing and Sichuan Province) during Spring and Autumn Period and Han Dynasty. Despite of extensive archaeological study of the bronze mou, scientific analysis of bronze mou was less, and no organic residue analysis has been undertaken on the bronze mou. In this study, four bronze mous dated to Han dynasty (206BC-220AD) with organic residues unearthed in three archaeological sites in Wushan, Chongqing were selected to be tested by portable X-ray fluorescent spectrometer (P-XRF) , and then be analyzed by Liquid chromatography Tandem Mass Spectrometry (LC/MS/MS). The alloy compositions results show that all the samples are copper-tin-lead ternary alloy. The proteomic analysis results confirmed that the bronze mou had been used as cooking utensils or containers. At the Tuchengpo Cemetery, soybeans were contained both in bronze mou M32:27 and bronze mou M38:39. There was no useful protein discovered in the bronze mou from the Shennvmiao Cemetery. Proteins of ginkgo and chicken were found in M16:12 at the Gaotangguan Cemetery. It indicates the residents in Wushan, Chongqing had a diversity of food sources around 2000 years ago. Furthermore, this study demonstrates proteomic analysis is highly effective in studying archaeological organic residues.