Provided are an sp2 carbon-containing composition that is highly conductive and that excels in the stability of conductivity over time, a method of manufacturing the sp.sup.2 carbon-containing composition, and a method of peeling graphite to obtain a graphene-containing composition. Further provided are a graphene quantum dot-containing composition and a method of manufacturing the graphene quantum dot-containing composition that provides an improvement in the productivity and the manufacturing cost. A method of manufacturing an sp2 carbon-containing composition according to the present disclosure includes a contact step of bringing a two-coordinate boron cation salt into contact with an sp.sup.2 carbon. Preferable examples of the two-coordinate boron cation include one expressed by the following formula (1). R1—B—R2 Formula (1) [In the formula, R.sup.1 and R.sup.2 are each independently a compound selected from the group consisting of a phenyl group, a mesityl group, 1,5-dimethylphenyl group, 1,3,5-triisopropylphenyl group, 1,5-diisopropylphenyl group, 1,3,5-tris(trifluoromethyl)phenyl group, and 1,5-bis(trifluoromethyl)phenyl group.]