Introduction: To evaluate the remineralisation effectiveness of enamel subsurface defect using marine skeletal specie - Meretrix meretrix (cockle shell) powder extract on human tooth enamel. Materials and Methods: Recently extracted 5 human 3rd molar teeth were sectioned at cement-enamel junction (CEJ)and included for the study. Later each tooth coronal portion was equally divided into fourparts of enamel blocks in order to obtain twenty blocks which were exposed to demineralization procedure and grouped as: Group I-subsurface demineralization cockle shell powder extract. Group II: subsurface demineralization + clinpro application being kept in artificial saliva for period of thirty days. The samples were assessed for X-ray fluorescence spectroscopy evaluation, micro hardness testing and atomic evaluation with Energy dispersive xray spectroscopy. The values were statistically calculated with one-way ANOVA and Tukey - Kramer multiple comparison test. Results: X-ray fluorescence spectroscopy displayed Calcium concentration in cockle shell of 98.3% & concentration of Phosphate 0.21% respectively. Group II (Clinpro) displayed highest potential in accelerating the remineralisation then Group I: CSEP (Cockle shell extract powder). The values of atomic evaluation displayed that quantitative volumes of Ca weight % and P weight % is statistically greater for both the groups. Group II (Clinpro) exhibited higher remineralisation efficiency then Group A (mussel shell extract). Conclusion: Marine shells with greater calcium composition can remineralise enamel subsurface defects.