Abstract: The interaction between chlorgenic acid and porcine pancreas lipase( PPL) was researched by fluorescence spectrophotometer,including the fluorescence quenching properties,calculating the binding constants and binding sites,inhibitory activity and inhibitory type of caffeic acid on porcine pancreatic lipase,effect of metal ions on the interaction.Experimental results showed that caffeic acid of had strong fluorescence quenching effect on porcine pancreas lipase,maximum absorption wavelength redshift,mainly belongs to static quenching. Binding constant under 25 ℃ and 37 ℃ 6.48 × 104 L / mol and 1.38 × 105 L / mol respectively,and the thermodynamic parameters Δ H > 0 and Δ S > 0,showed that combination was a spontaneous endothermic reaction,the main force of hydrophobic forces.Inhibitory type of caffeic acid on pancreatic pancreatic lipase was noncompetitive inhibition,inhibitory activity was IC50( 0.88 ± 0.07) mg/m L.When there were four kinds of metal ion( Cu2 +,Ca2 +,Fe3 +,Fe2 +) binding constant and binding points were increased,that metal ions,to a certain extent,promoted the combination of caffeic acid and pancreatic lipase.