An S band surface acoustic wave(SAW) filter with center frequency of 3.4 GHz was developed in this work. The filter adopted an impedance element structure composed of a new type of resonator, which can improve the resistance to electrostatic damage(ESD) protection of pyroelectric effect, and improve the power handling ability to a certain extent.Furthermore,a kind of chip scale packaging(CSP) substrate with size of 2.0 mm×1.6 mm was developed.The electric connection between the chip and CSP substrate was realized by the flip-chip process, thus the electromagnetic parasitic influence was reduced.The developed S band SAW filter has center frequency of 3.408 GHz,insertion loss of 2.23 dB, above 30 dB the stopband suppression of greater than 30 dB at 8 GHz at the far end, the measured power handling ability of 30 dBm.