Abstract: In this work, the tetrahedral unit cell model, which was suitable for low-density foam, was modified to predict the creep properties of foam materials in a broader range of density varieties, by considering the volume correction at the intersection point of struts. The influences of the bending and shearing deformation mechanisms of the inclined struts on the creep strain rate were investigated based on the modified model. The results indicate that the bending deformation mechanism of struts dominates the creep rate of the foam with a relative low density, and the shearing deformation mechanism dominates the creep rate of the foam with a relative high density. A comparison with the experiment results verified the predictions of the present work.