A solvent-free silicone composition for release paper, comprising a mixture prepared by i) subjecting the organopolysiloxane (I) which is composed of R13SiO1/2 units, SiO4/2 units and (HO)SiO3/2 units, and has an OH group content of from 0.02 to 0.1 mol/100 g, to a partial condensation reaction in an organic solvent in the presence of an alkaline catalyst and the organopolysiloxane (II) represented by the following formula (2), and ii) removing the organic solvent, said mixture having an OH group content of less than 0.02 mol/100 g. The composition forms a tight-release layer stable with time.