Abstract: LTCC is an effective method for realizing small size, lightweight, high performance and high reliability T/R module of air-borne, satellite-borne and ship-borne phased array radars. However, LTCC research has been severely restricted by the shortage of commercialized microwave LTCC materials in our nation which is attributed to the disadvantage of technology. In this paper, the application of domestically produced CaO-B₂ O₃-SiO₂ system LTCC green tape in X-band T/R module is intensively studied. The technological property, matching property with paste and microwave property of this LTCC green tape are described. Furthermore, X-band T/R modules based on this LTCC green tape are fabricated, and satisfy the technique standard of phased array radar. This study provides useful results for the localization of LTCC materials.