Abstract: With Takayanagi's two-phase blended model and Ziege's modified equation,and by taking composite interface as a medium phase (interphase),this paper derives a three-phase blended model of dynamic viscoelasticity from one-dimension FRP(fibcr reinforced polymer composite),and obtains the mixing parameters of geometric Structure in the interfacial layer (r,V,λ and medium parameter Band every dynamic viscoelastic parameter of interphase.Those parameters can be gained from the result of the dynamic viscoelastic experiment with FRP.Through the experiment of unidirectional fiber reinforced polyester with the given model,the result shoes that the thickness of interphaser and the fraction of volume V change with the temponature,and so do the dynamic viscoelastic parameters of interface.The interchange takes place between in1erphase and matrix phase.