Abstract: The pH response indicator membranes were prepared by solvent casting with k-carrageenan and purple potato anthocyanins at different pH values（i.e.,4,5,6,7）.The structures of the indicator membranes were characterized by UV-vis and FT-IR.The thickness,mechanical properties,rheological properties,and full-fat sterilized emulsion deterioration monitoring test of the film were evaluated.The results showed that k-carrageenan and purple sweet potato anthocyanins could bind by electrostatic or hydrogen bonding.Compared with pure carrageenan membranes,the tensile strength of the membranes formed at pH=4 and pH=5 was slightly increased,and the tensile strength of the membranes formed at pH=6 or pH=7 was significantly increased（（13.13±0.78） MPa,（12.99±0.56） MPa）,and the elongation at break decreases with the increase of pH.Anthocyanins of purple potato had no significant effect on the thermal stability of the membrane.The pH response indicated that the membrane exhibits a distinct color change in different buffer solutions.After fresh milk was stored at 25 ℃ for 72 h,the P7 membrane showed obvious color change.So the membrane has good physical properties and obvious pH response performance,and has potential application value in food preservation intelligent packaging.