Objective To assess the remineralization property of several toothpastes on initial enamel lesions. Methods Bovine enamel blocks with in vitro produced initial lesion were used. The lesions were subjected to a pH-cycling regime for 12 d, with one of five treatments: NaF（positive control） group, pro-arginine group, casein phosphorylation of protein group, toothpaste with 0.11% fluoride group and with distilled and deionized water （DDW） group for negative control. The samples were subsequently evaluated using a microhardness tester, polarised light microscopy（PLM） and confocal laser scanning microscope（CLSM）. Results Surface hardness measurements revealed pro-arginine group, casein phosphorylation of protein group and NaF group had significantly greater effect on enhancing remineralization than that of toothpaste with 0.11% fluoride group（P
