Provided is a brain function-improving composition which can inhibit binding of homocysteic acid to a receptor (NMDA receptor) and, at the same time, decrease the binding ability of homocysteic acid per se to the receptor to thereby improve reduction in the brain function caused by the toxicity of homocysteic acid. The brain function-improving composition comprises 0.3-0.5 part by weight of a cinnamic acid derivative compound and 0.5-0.7 part by weight of a calcium hydride powder. Also, the brain function-improving composition is characterized by further comprising 0.4-0.6 part by weight of a green tea powder, 0.4-0.6 part by weight of a cocoa powder, 0.25-0.35 part by weight of a hydroxysilica powder, and 0.9-1.1 parts by weight of a dry Angelica shikokiana Makino powder.
