Abstract: Bonding interconnect is the critical technique for realizing the interconnect of microwave multichip module(MCM). The height, distance and number of wires of bonding interconnect have important effects on its microwave characteristics. In this paper, commercial 3D electromagnetic analysis software HFSS and microwave circuit design software ADS were used to model, simulate and optimize for the microwave characteristics of bonding interconnect in low temperature co-fired ceramics(LTCC) microwave MCM. The simulations were shown to be in good agreement with the experimental results.