AbstractTwo different types of Lower Hybrid Current Drive (LHCD) antenna having high-heat resistant property are developed according to a pulse length and/or working frequency. In the first type of LH antenna, heat resistive material is installed at the antenna mouth only and should be attachable using bolts. This heat-resistant mouth is exchanged for a new one when it is damaged. The heat-resistant mouth is made of Carbon Fiber Composite (CFC)-block bonded with stainless steel-base machined to fit the waveguides. This mouth has no Cu-plating for reducing rf-losses, because the antenna is designed to operate during 10–100 s injection of 2 GHz in JT-60SC. The second antenna consists of a compact multi-junction (MJ) part and a power divider designed for the next generation tokamak machine like ITER. This MJ must be made of low-Z material as a plasma facing component allowing no degradation in confinement. The test module for the MJ is made of rods and plates of CFC with Cu-plating ∼30 cm in length. The test module shows transmitted power availability up to 45 MW/m2 over 1000 s with cooling at 3.7 GHz. For improvement of transmitted power availability, R&D of strong Cu-plating on CFC surface has been progressed using an electrochemical method.