NOVELTY - A high-basis weight carbon fiber sheet (10) is obtained by fixing single twisting fiber bundle or jointed twist fiber bundle in a fiber material, and has fiber basis weight of more than 800 g/m2 to 6000 g/m2. The single twisted fiber bundles (11) are produced by bundling 50000-60000 carbon fiber monofilaments (f) to form carbon fiber strand (F) and twisting the carbon fiber strand by 5-50 turns per meter. The unitedly twisted fiber bundles (12) are produced by assembling multiple carbon fiber strands obtained by bundling 50000-60000 carbon fiber monofilaments.    USE - High-basis weight carbon fiber sheet is used for resin-transfer molding process for producing fiber-reinforced plastic material (claimed) for blade of windmill, vehicle, boat and ship.    ADVANTAGE - A high-basis-weight carbon fiber sheet has high bending strength.    DETAILED DESCRIPTION - A high-basis weight carbon fiber sheet is obtained by fixing single twisting fiber bundle or jointed twist fiber bundle in a fiber material, and has fiber basis weight of more than 800 g/m2 to 6000 g/m2. The single twisted fiber bundles are produced by bundling 50000-60000 carbon fiber monofilaments to form carbon fiber strand and twisting the carbon fiber strand by 5-50 turns per meter. The unitedly twisted fiber bundles are produced by assembling multiple carbon fiber strands which are each obtained by bundling 50000-60000 carbon fiber monofilaments and twisting the resulting assembly by 5-50 turns per meter. An INDEPENDENT CLAIM is included for RTM construction method, which involves placing carbon fiber sheet to formwork, injecting and hardening resin, and molding a fiber-reinforced-plastics material. The viscosity of resin during injection is 30-300 mPa.second.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic perspective view of carbon fiber sheet.    Carbon fiber strand (F)    Carbon fiber monofilament (f)    High-basis weight carbon fiber sheet (10)    Single twisted fiber bundle (11)    Unitedly twisted fiber bundle (12)