Objective To evaluate the capability of red fluorescence analysis using quantitative light -induced fluorescence（QLF） methods, comparing with green fluorescence analysis, for detection and monitor of enamel early carious lesions on smooth surfaces. Methods 96 students with early enamel carious lesions were required to perform supervised tooth brushing with 0.145% F- dentifrice for six months. QLF images were taken from smooth surfaces of erupted maxillary anterior teeth at baseline and six months later. Both red fluorescence and green fluorescence analysis of carious lesions were carried out. QLF metrics including the areas of lesions（Ar, Aw）, average fluorescence （△R, △F）, total fluorescence（R, △Q）were exported. Results Pearson correlation coefficients between variables of red and green fluorescence were 0.89（Ar vs Aw）, 0.54（△R vs △F） and 0.72（lgR vs lg△Q）. Significant decreases were exhibited by all the quantitative variables at sixth month compared to those at baseline （P
