PURPOSE: To produce the subject silicone compound useful as a modified silicone oil, etc., by reacting a tetraalkoxysilane, a glycidoxypropylalkyldialkoxysilane and methacryloxypropyltrialkoxysilane.

CONSTITUTION: This compound is synthesized by conducting a cohydrolysis and condensation reaction of (A) a tetraalkoxysilane of the formula Si(OR1)4 (R1 is a 1 to 8C saturated alcohol-derived alkoxy), (B) a 3- glycidoxyprolylalkyldialkoxysilane of formula I (R is a 1 to 8C saturated hydrocarbon group, an alkenyl, especially preferably a 1 to 2C saturated hydrocarbon or vinyl; R2 is same as R1) and (C) a 3-methacryloxypropyltrialkoxysilane of formula II (R3 is same as R1) in the presence of an acid catalyst in a condensed organotin catalyst-containing mixture solvent with water in an amount of 3 to 4 times the total amount of the silanes on molar base. For example, a compound represented by formula III [(x') is 2.0 to 0.5; (m), (n) and (l) are each a positive integer of ≥3], having a terminal silanol group and exhibiting an oil state at ordinary temperatures is exemplified.