The Eddy Dissipation Concept (EDC), as a promising flame prediction model, is reviewed comprehensively. Instead of strong modifications of the standard EDC constants to fit experiments, a modification method of the EDC constants based on the fuel jet Reynolds number is presented in this work and used to predict a simple jet nonpremixed syngas Sandia Flame CHN–B and a piloted CH4/air partially premixed Sandia Flame D. Compared with the experiments, the predictions show the two flames are properly reproduced with the modified EDC constants. Some over-predictions might be attributed to the under-estimation of turbulence. The microscale and the macroscale Damköhler numbers are presented showing decreasing trends with the increased Reynolds number. Three clear combustion regions in the two flames are firstly identified from the results of the net reaction rate of OH. The reaction heat in the fuel-rich region is found larger than that in the fuel-lean region for Flame D. The contours of the net reaction rate of OH show a stronger reaction region in the fuel-lean side for Flame CHN–B and in the fuel-rich side for Flame D. The predictions with the modified EDC constants agree with the experiments better than those with the standard EDC constants.