The present invention relates to a method for producing an organopolysiloxane compound having a structure in which a poly(N-acylalkylene imine) segment containing a repeating unit represented by the following general formula (1) is bonded to a terminal end and/or a side chain of an organopolysiloxane segment, the method including the steps of (a) subjecting a cyclic iminoether compound represented by the following general formula (I) to ring opening polymerization in a solvent to prepare a solution of a terminal-reactive poly(N-acylalkylene imine); (b) mixing a modified organopolysiloxane containing an amino group bonded to a terminal end and/or a side chain of a molecular chain thereof with a solvent to prepare a solution of the modified organopolysiloxane; (c) mixing the terminal-reactive poly(N-acylalkylene imine) solution prepared in the step (a) with the modified organopolysiloxane solution prepared in the step (b) to react the amino group contained in the modified organopolysiloxane with the terminal-reactive poly(N-acylalkylene imine); (d) adding a basic substance to a reaction product obtained in the step (c); and (e) removing the solvents from a mixture obtained after the addition in the step (d) at a temperature of from 100 to 200° C.: wherein R1 is a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, an aralkyl group or an aryl group; and n is a number of 2 or 3.