Objective To develop an uncertainty study model of the enzymological reference method to systematically research the uncertainty influencing factors of 6 enzymological reference methods ALT,AST,LDH,AMY,GGT and CK for determining the key factors influencing the reference method and better guiding the establishment and operation of the enzymological reference methods.Methods The uncertainty of the six enzymological reference methods was evaluated by the theoretical evaluation com-bined with the experiment design according to series of standards including JJF1059-1999 Evaluation and Expression of Uncertainty in Measurement,JJF1135-2005 Evaluation of Uncertainty in Chemical Analytical Measurement,CANA-GL06 Guidance on Evalua-ting the Uncertainty in Chemical Analysis and CNAS-CL33 Guidance on the Application of Testing and Calibration Laboratories Competence Accreditation Criteria in the Field of Clinical Enzymology Reference Measurement.Results The established enzymo-logical uncertainty study model was C=ΔAΔt · 1ε · 1L ·V 1 +V 2 +V SV ·fT ·f pH ·fλ·fkit ·fresult .Conclusion The uncertainty e-S valuation model is set up and successfully applied in the uncertainty evaluation of the six enzymological reference methods.