Abstract: A novel miniature broadband balun based on LTCC is designed and presented in this paper. This kind of balun is derived from Marchand microstrip balun. For the realization of miniaturization, LTCC multilayer 3D structure, spiral broadband coupling stripline structure (SBCS) and capacity end-loaded stripline structure all have been applied comprehensively. Discussion about the design thought, operation theory and 3D model are proposed. The operation frequency ranges from 0.9 GHz to 2.3 GHz. The balun is fabricated and measured with the dimension of 1.8mm×1.2mm×1.0mm. Measured results show the performance is all right. The return loss is low, amplitude balance is fine and phase consistency is good. The results from the simulation and those from the measurement are in good agreement.