Abstract: Critical heat flux for axial non-uniform heat flux distribution in rectangle narrow channel was studied in this report.During the test,electric heating were adopted,and the axial direction power loaded were truncation cosine distribution.The deionized water was heated.The test result indicated that CHF with non-uniform axial heat flux distribution was lower than CHF with uniform axial heat flux distribution.A correction factor was used to analyze the test data.The semi-empirical relation of correction factor of CHF with axial non-uniform heat flux distribution had been obtained.Comparing to the existing correction factor models,it revealed that the proposed semi-empirical relation predictive CHF with axial non-uniform heat flux distribution in rectangle narrow channel was most accurate.