Hydrogels are viscoelastic material, soft and fragile materials that contain high water percent. These properties cannot sustain high axial compression loads. In this study, a foam was infused into hydrogel, agarose, to enhance the mechanical properties of the hydrogel/foam composite. Besides, it is difficult to measure the mechanical properties of the hydrogel alone specifically in tension because of the slipping in the grip during using the common tensile test. Therefore; the goal of this study is to investigate the influences of infused cellulose foam into the prepared hydrogels on the mechanical properties of the hydrogels by conducting the unconfined compression on hydrogel/foam composite and the hydrogel alone. It is also to utilize the strain energy density functions (SEDFs) to determine a suitable constitutive model that represents the nonlinear behavior of the materials. It is to predict the behavior of these materials out of range of the test (i.e. in tension) by implementing a Finite Elements Analysis (FEA) using ABAQUS. The results showed that the strength of the hydrogel/foam composite was significantly greater than hydrogel alone. All hyperelastic models have well defined the nonlinear behavior of the experimental data. FEA results in tension are in good agreement with those predicted using hyperelastic models.