Abstract: The approach combining ultra-high performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) for determining hyaluronic acid in dairy products was proposed in this study. The samples were degraded by hyaluronidase, diluted with acetonitrile, and then purified by PRIME HLB cartridge. The analysis was conducted on a BEH Amide column (2.1 mm×100 mm, 1.7 μm) by gradient elution using 0.2% concentration of aqueous ammonia solution and acetonitrile (containing 0.2% ammonia) as mobile phases. Qualification was achieved by negative electrospray ionization with multiple reaction monitoring (MRM). Meanwhile, the external standard method for quantitation was applied. In accordance with the results, the recoveries of hyaluronic acid in dairy products were 91.4%~106.2%, and RSDs were 2.3%~6.7% at the addition levels of 0.5~200 mg/kg. Presumably, with a limit of quantification of 0.5 mg/kg, the demonstrated method was easy and feasible for quantifying the hyaluronic acid in dairy products. This method was used to detect commercially dairy products, and the tested samples meet the standard requirements.