Composite reinforcing material and molding material

A method of producing a composite reinforcing material, comprising a step of kneading at least a graphite-based carbon material and a reinforcing material into a polymer base material, so that graphene is partially exfoliated from the graphite-based carbon material and dispersed in the base material, the graphene being a crystal of a mean size of 100 nm or more and formed in a flake-like or sheet-like shape having 10 or less layers, a proportion of the graphene having 10 layers or less being 25% or more after the kneading step,

• the graphite-based carbon material having a rhombohedral graphite layer (3R) and a hexagonal graphite layer (2H), wherein a Rate (3R) of the rhombohedral graphite layer (3R) and the hexagonal graphite layer (2H), based on an X-ray diffraction method, which is defined by following Equation 1 is 31% or more:
• Rate (3R)=P3/(P3+P4)×100 Equation 1
• wherein
• P3 is a peak intensity of a (101) plane of the rhombohedral graphite layer (3R) based on the X-ray diffraction method, and
• P4 is a peak intensity of a (101) plane of the hexagonal graphite layer (2H) based on the X-ray diffraction method.