We developed novel interconnection technology for heterogeneous integration of MEMS and LSI multi-chip module, in which MEMS and LSI chips would be horizontally integrated on substrate and vertically stacked each others. The cavity chip composed of deep Cu TSV-beam lead wires was developed for interconnecting MEMS chips with high step height of more than 100um. Fundamental characteristics were successfully obtained from pressure sensing MEMS chip with 360μm thickness, which was connected to the substrate by the cavity chip. MEMS and LSI chips were vertically integrated by using the cavity chip without changes of chip design and extra processes. This interconnection technology can give strong solution for heterogeneous integration of MEMS and LSI chips multi-chip module.