Abstract: An implementation method of the miniaturized dual-band filter based on a quadruple-mode resonator is proposed. The quadruple-mode resonator is realized by adding two open-circuit branches to one side of the two-mode resonator with an open-circuit branch loaded at both open-circuit ends after bending, which could reduce the size of the filter. In addition, the equivalent capacitance method of lumped capacitance instead of open-circuit transmission lines is used to further realize the miniaturized design of the filter. The introduction of the source-load coupling structure produces transmission zeros that enhance out-of-band suppression. The dual-band filter realized by LTCC（Low Temperature Co-fired Ceramic） has good performance. The insertion loss in two passbands is less than 1.5 dB, the return loss is greater than 15 dB, and the out-of-band suppression is more than 20 dB. The stopband suppression at the high-frequency passband and between the two passbands is more than 30 dB. The volume is only 4.8 mm×4.2 mm×1.5 mm. The measurement curves show a good match with the HFSS simulation. The quadruple-mode dual-band filter has advantages of high selectivity and small volume, and has good application value, and provides a new idea for the design of LTCC multi-band bandpass filters.