Abstract：For the homogeneous viscoelastic body with constant Poisson ratio m during creep，the viscous part of the total strain increment，when generalized to 3D based on 1D，was achieved by substituting the operator of for 1/E in the expression of linear elastic strain，keeping the Poisson ratio matrix [A] constant. With this method，the matrix form of the 3D viscous strain increment for the standard linear solid model is obtained；and the corresponding tensor form is derived，which can be also generalized to the common viscoelastic body with constant Poisson ratio. Then，based on the elasto-viscoelastic correspondence principle，the 3D creep equation of viscoelastic body with constant Poisson ratio is achieved using creep compliance. The viscous strain increment is obtained and expressed in matrix form when this creep equation is applied to the material with the standard linear solid model. Compared with the former method，the expression of viscous strain increment is different，but both methods are essentially uniform when the relations of model parameters of two methods are identified by one-dimensional creep test. Thus the constitutive equations of viscoelastic body with constant Poisson ratio are virtually the same with the two different methods.
