A way of designing the parallel coupled microstrip band pass filter has been presented.The filter with the center frequency of 1.0 GHz and band pass 100 MHz has been designed and simulated by using the software ADS.Since the parasitic and coupling factors are neglected in the ADS circuit simulation and resulted in great errors,the momentum 2.5D is used to simulate the filter model multi dimensionally and the structure parameters of the filter have been optimized.The ceramic substrate with good performance has been used to fabricate a physical filter.〖HJ〗 The test results agree well with the simulation and design results as well as the design specifications.The filter has good reflection characteristics of the ports,the pass band attenuation is less than 2 dB;the port reflection coefficient is less than -20 dB;and the stop band attenuation is more than 40 dB that meet the requirements of the technical specifications.