Abstract: Experimental and numerical studies on vertical water entry of hyperelastic spheres are performed at low velocity. The unique cavities shapes and deformation behaviors of hyperelastic spheres are observed by experiments. With the interpolation of deformation supported radial basis functions (RBF) and mapping of force used principle of virtual work, the vertical water entry of hyperelastic spheres is simulated numerically. Meanwhile, the validity and reliability of the numerical method are validated by comparing with cavity shape, displacement curve and deformation coefficient curve obtained from the experimental data. The numerical results show that compared with the rigid spheres, we find that the length of air cavities formed elastic spheres is shorter, and the diameter of air cavities formed elastic spheres is bigger because of the sphere deformation and energy loss. Moreover, the surface pressure of the hyperelastic sphere after water entry varies more widely than that of the rigid sphere due to the local turbulence and deformation.