Abstract: The nano-polypropylene(PP) fiber was modified with n-butyl acrylate bymeans of ultraviolet(UV) radiation to obtain a new highly oil-absorbing material.The optimum conditions determined by orthogonal experiment were as follows:irradiation time,concentrations of monomer n-butyl acrylate and photosensitizer diphenylmethanone were 1 h,33.3% and 0.2%,respectively.The original and grafted fibers were characterized by Fourier transform infrared(FT-IR) spectrometer and the results indicated that n-butyl acrylate had been successfully grafted onto the surface of PP fiber.Oil absorption capacity was investigated at different grafting degree,time,temperature and pH value.The adsorption kinetic data for motor oil coule be well described pseudo-second order rate model.Experimental data showed that absorption capacity of nano polypropylene and modified materials for motor oil were 35.5 and 28.5,respectively.The adsorption properties of modified materials was significantly improved after grated.Temperature had obvious influence on the oil absorption of the modified nano polypropylene fiber,which is related to the oil type and viscosity.With the increasing of pH value,adsorption capacity of oilmodified nano polypropylene fiber increased rapidly.