An organosilicon compound having not more than 200 silicon atoms per molecule is provided. The organosilicon compound is represented by the following average compositional formula (I): YaR1bSiO(4-a-b)/2 wherein R1 is an alkyl group having 1 to 12 carbon atoms, alkenyl group having 2 to 12 carbon atoms, aryl group having 6 to 20 carbon atoms, alkoxy group having 1 to 6 carbon atoms, or a hydroxyl group; Y is a specific acylphosphinate residue; and subscripts a and b are numbers satisfying the following conditions: 0