An electron emission source includes a carbon-based material and resultant material formed by curing and heat treating at least one silicon-based material represented by formula (1), (2), and/or (3) below: where R1 through R22 are each independently a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C1-C20 alkoxy group, a substituted or unsubstituted C1-C20 alkenyl group, a halogen atom, a hydroxyl group or a mercapto group, and m and n are each integers from 0 to 1,000. An electron emission device and an electron emission display device include the electron emission source. A composition for forming electron emission sources includes the carbon-based material and the silicon-based material. A method of forming the electron emission source includes applying the composition to a substrate; and heat treating the applied composition. The adhesion between the electron emission source including the cured and heat treated resultant material of the silicon-based material and a substrate is excellent, and thus the reliability of the electron emission device including the cured and heat treated resultant material of the silicon-based material can be enhanced.