Abstract: A novel high performance planar filter is developed based on the half mode substrate integrate waveguide(HMSIW)with complementary splitring resonator(CSRR)etched on the waveguide top. The proposed structures allow the implementation of a forwardwave passband propagating below the characteristic cutoff frequency of the waveguide so that the filter is operated below the characteristic cutoff frequency of the waveguide. The band pass resonant frequency can be tuned easily by changing the design parameter of CSRR. Arbitrary bandpass microwave filter are easier to be realized by using the characteristics. The application of the HMSIW and CSRR combination technique for the design of miniaturized band pass filter. This filter shows advantages in terms of the compact size, low loss, easy fabrication and integration with other circuit.