Abstract: The aqueous hair cleansing agent of the present invention comprises the following components (A) to (C): (A) an anionic surfactant; (B) side chain amino-modified organo polysiloxane having long chain alkyl at both ends represented by the following general formula (1) (R2R32)SiO—(R32SiO)x—(R3R4SiO)y—Si(R2R32)??(1) wherein formula (1), R2 represents linear or branched alkyl group having 12 to 30 carbon atoms 12 to C30, R3 represents substituted or non-substituted monovalent hydrocarbon group having 1 to 6 carbon atoms, and R4 represents 3-aminopropyl group or N-(2-aminoethyl)-3-aminopropyl group, and x is an integer number of 1 to 2,000, y is an integer number of 1 to 100, and nitrogen content is 0.31 to 2 mass %; (C) a cationic galactomannan and water.