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 (deltaR, deltaF), total fluorescence (R, deltaQ) were exported. RESULTS: Pearson correlation coefficients between variables of red and green fluorescence were 0.89 (Ar vs Aw), 0.54(deltaR vs deltaF) and 0.72 (lgR vs lgdeltaQ). Significant decreases were exhibited by all the quantitative variables at sixth month compared to those at baseline (P <0.05). CONCLUSION: Red fluorescence analysis using QLF system could quantify the mineral content and monitor the recovery of carious lesions. It could be used to evaluate methods for prevention and cure of caries.