Objective：To compare the effect of casein phosphopeptide-amorphous calcium phosphate（CPP-ACP），casein phosphopep－tide-amorphous calcium phosphate fluoride（CPP-ACPF），tri-calcium phosphate fluoride（TCP+F） and Duraphat fluoride var－nish on surface microhardness and surface morphology after toothbrushing abrasion of eroded enamel. Methods：Impacted mandibular third molars were collected at clinic and 50 sam－ples with hardness between 280-330 HV were selected. The samples were processed into enamel slabs and then were randomly divided into five groups. The samples were first immersed into Co－ca-Cola for 5 min，5 times a day for 5 days. Then erosive enamel samples were subjected to brushing abrasion with an electric tooth－brush 2 N brushing load for 3 min，2 times a day for 5 days. Distilled water，CPP-ACP，CPP-ACPF，TCP+F and Duraphat were re－spectively applied during brushing interval and abrasion-remineralization-erosion treatment was provided for ５ days. Microhardness of enamel surface before and after the treatment was measured by microhardness tester and morphology changes of enamel surface was observed by scanning electron microscope（SEM）. Results：Microhardness in CPP-ACP and CPP-ACPF group was decreased，having no significant difference compared with that of distilled water group（P ＞0.05）. Microhardness in TCP+F and Duraphat group was significantly higher than that of distilled water group（P<0.05）. Smooth enamel surface was observed with SEM in other four groups except in distilled water group. Conclusion：Duraphat and TCP+F can prevent the abrasion of constant acid eroded enamel.