Abstract: We establish a mathematical model for evaluation of the uncertainty of detecting Quinolones residues in aquatic products by high performance liquid-MS/MS (HPLC-MS/MS), and analyze the sources of uncertainty in determination. By calculating the components of all uncertainties, relative combined standard uncertainty and expand uncertainty, we obtain a report of uncertainty of Qinolones. The results show that the main source of the uncertainty comes from HPLC-MS/MS and preparation of standard solution.