A carbon fiber reinforced substrate comprising a fabric composed of carbon fiber bundles and a first resin adhering to the fabric. Each of the carbon fiber bundles comprises numerous continuous carbon filaments, has the tensile modulus of 210 GPa or more, and has the fracture strain energy of 40 MJ/m.sup.3 or more. The amount of the first resin adhering to the fabric is in a range from 1 to 20 parts by weight per 100 parts by weight of said fabric. A preform comprising a laminate composed of plural layers of the carbon fiber reinforced substrate, wherein the layers are integrated by means of the first resin. A composite comprising the preform impregnated with a matrix resin.