To provide a new diorganopolysiloxane having an organopolysiloxane residue containing 7C alkyl group on a molecular chain terminal.

The diorganopolysiloxane is expressed by general formula: X-R2-(R12SiO)nR12Si-R2-X. In the formula, R1 is a 6C monovalent hydrocarbon group free from aliphatic unsaturated bond; R2 is an alkylene group; X is an organopolysiloxane residue expressed by an average unit formula: (YR12SiO1/2)a(SiO4/2)b (R1 is same as defined above; Y is a single bond, hydrogen atom, the above R1 group, an alkyl group containing epoxy group, an alkoxysilylalkyl group or a 7C alkyl group, provided that at least one Y is a single bond and at least one Y is a 7C alkyl group in one molecule; a is a positive number; b is a positive number; and a/b is 0.2 to 4.0), R1 or an alkenyl group, provided that at least one X is the above organopolysiloxane residue; and n is an integer of 1-1,000.