In order to achieve compact dualband filters with high selectivity,based on LC equivalent circuit analysis method and microwave network analysis method, by establishing the equivalent model,carrying out the equivalent circuit analysis and admittance matrix analysis of the transmission model,a novel LTCC dualband filter structure operating at GSM/WLAN is proposed in this paper.The structure is made of LTCC dielectric substrate of Ferro A6 with the dielectric constant of 5.9,thickness of 0.1 mm,and the high selectivity dual frequency filtering characteristics of transmission zeros on both sides of the passbands are realized in the size of 7 mm×7 mm×0.5 mm.This research has enriched and developed the design method of LTCC dualfrequency filter.