In this thesis, we propose a miniaturized LTCC balanced filter that integrates bandpass filter (BPF) and balun. In order to reject interferences, we have the transmission zero of out-band by extra capacities and inductances in the prototype of Second-Order BPF. On the other hand, we miniaturize the balun by revising the length of couple-line with four shunt capacities. The practice size of the miniaturized balanced filter is 2.0mm x 1.25mm x 0.95mm.The insertion and return losses are less than -2.5dB and -20dB over operating frequency band, respectively. The phase difference is less than 5 ¢X, and the amplitude difference is within -0.5dB in operating frequency band. The size is the smallest in the similar commercial product and relative journal.