In the current work, interpenetrating polymer network (IPN) silicone hydrogels are prepared by UV-initiated polymerization of acrylate monomers including siloxane macromer, methacryloxypropyl tris (trimethylsiloxy) silane (TRIS) and N,N-dimethylacrylamide (DMA)/N-vinyl-2-pyrrolidone (NVP) in the presence of free radical and cationic photoinitiators. The polymerization mechanism is investigated preliminarily by the formation of gel network. The morphology of the hydrogels is characterized by fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and transmission electron microscope (TEM). The results show that the IPN hydrogels exhibit a heterogeneous morphology. The surface wettability is examined by the contact angle goniometer. The result reveals that the IPN silicone hydrogels possess hydrophilic surfaces with the lowest water contact angle of 59 degrees. Furthermore, the oxygen permeability of the hydrogels is measured by an oxygen transmission tester. The results indicate that the IPN silicone hydrogels have excellent oxygen permeability with the highest Dk of 226 barrer. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 116: 2749-2757, 2010