Oxygen plasma was employed to treat a fluorosilicone acrylate RGP contact lens material (Boston EO) in order to improve surface hydrophilicity. X-ray photoelectron spectroscopy (XPS) was applied to characterize the surface chemical state. The surface morphology and hydrophilicity were investigated by scanning electron microscope (SEM) and contact angle measurement respectively. The surface contact angle measurement indicated an evident improvement of surface hydrophilicity after plasma treatment. XPS results indicated that the incorporation of oxygen and the transform of -Si-CH3 into hydrophilic -Si-O after plasma treatment were the main reasons for surface hydrophilicity improvement. SEM showed some decrease of surface roughness under moderate plasma condition. But plasma with higher power would etch the material surface.