1D simulation of streamer discharge formation and propagation for a non-uniform electric field(point-to-plane geometry)in CF3I at atmosphere is presented.Results show Streamer discharge of CF3I including the phase of electron avalanche and the phase of streamer.The total formative time of streamer discharge in CF3I is about 2.2ns,which the first 0.6ns is taken up with the avalanche development travelling a distance of 0.078cm from cathode,and the nextl.6ns by streamer development.Space charge and Photo-ionization have a great influence on the development of gas streamer discharge.