Abstract: Acid phosphatase(ACPase) from the sperm of PIC pigs(PIC344) could be activated by these ions of K⁺,Mg ²⁺ ,Ca ²⁺ ,Ni ²⁺ ,Mn ²⁺ , while inhibited by Cu²⁺ ,Cd ²⁺, Fe ²⁺ ,Zn ²⁺ . The concentrations of these ions rang from 1 mmol/L to 5 mmol/L. ACPase was inactivated by EDTA . The ability of metal ions activate the ACPase one by one in order for Mg ²⁺ > Ni ²⁺ > Mn ²⁺ > K⁺ > Ca ²⁺ . The ability of metal ions inactivate the ACPase one by one in order for Cu ²⁺ > Cd ²⁺ > Fe ²⁺ > Zn ²⁺ .Cu ²⁺ and Cd ²⁺ were selected for determining types of inhibition. The results show that Cu ²⁺ and Cd ²⁺ were noncompetitive inhibitors by using LineweaverBurk method.Their Ki values were determined by Dixon method,which respectively were 0.58×10^-3 mol/L， 9.44×10^-3 mol/L.The Fluorescent spectras of Mg ²⁺ ，Ca ²⁺ ，Cd ²⁺ ，Cu ²⁺ indicate that the fluorescent spectrum strength to decrease, their maximum exit wavelengths were constant. The results explain that these metal ions influence the conformation of ACPase.