Objective In order to explore the microscopic mechanism of pathological clotting plasma interaction,we designed the intrinsic coagulation contact activation experiments to study how the endogenous coagulation factors induced procoagulant surface and the induced conditions.Methods Clean glass beads and silane glass beads were used,then we got different hydrophilic properties of procoagulant particle surface to determine the relationship between the activation of factor Ⅻ and hydrophilic properties of surface;buffer PBS was used to wash procoagulant surface,and then the surface was contact with platelet-poor plasma.We compared the clotting time to study the effects of plasma protein on clotting time.Results (1) Activation of FⅫ-FⅫa in the hydrophilic surface exhibited specific properties,the activation reaction in a hydrophobic surface significantly decreased (P<0.0001),and much more FⅫa was activated when FⅫ was contacted with a hydrophobic surface;(2) The FⅫ activation rate on hydrophobic surface was significantly decayed,and less products were obtained,however,activation FⅫ with a hydrophobic surface was binding tightly (P<0.0001),which was consistent with the result about the protein with a hydrophobic surface adhesion;(3) When the procoagulant activation was on the surface of 500mm2 and 30min incubated time,the clotting time and the active product of factor Ⅻ were much more stable.Conclusions Studies had shown that the surface energy depended on “catalytic potential” to promote FⅫ-FⅫa activation;When the coagulation surface area was the same,the activation rate and the amount of activation within PPP plasma FⅫ were significantly lower on the hydrophobic surface than the hydrophilic surface.On the contrary of the protein with a hydrophobic surface activation,FⅫ-full plasma activation on the hydrophobic surface were more slow than the hydrophilic surface which results in the appearance of a surface-energy-dependent catalytic potential.