AbstractA simple procedure for measuring two independent material properties of a viscoelastic material is proposed. Poisson's ratio is directly measured using digital image correlation during dynamic viscoelasticity test. Therefore, the complex Poisson's ratio as well as the complex modulus is simultaneously obtained from same specimen under same condition. The effectiveness of the proposed method is demonstrated by measuring the material properties of a soft epoxy resin. The measurement example shows that the master curves of the time‐dependent Poisson's ratio as well as other material properties for the wide range of the reduced time can be obtained by the proposed procedure.