Packing material for liquid chromatography

A packing material for liquid chromatography, comprising particles having a silicone polymer film coated on substantially the entire surface thereof, the packing material being produced by a process comprising the steps of: (a) bringing at least one silicone compound having the general formula (I): wherein R1, R2, and R3 represent, independently, a hydrocarbon residue having 1 to 10 carbon atoms, which may be substituted with at least one halogen atom, R4, R5, and R6 represent, independently, hydrogen ora hydrocarbon residue having 1 to 10 carbon atoms, which may be substituted with at least one halogen atom, a is zero or an integer of 1 or more, b is zero or an integer of 1 or more, c is zero or 2, and a + b + c is 3 to 300, into contact with particles, whereby the silicone compound is polymerized on substantially the entire surface of the particles, and(b) crosslinking unreacted Si-H groups in the presence of a catalyst, or(c) carrying out an addition reaction of a vinyl compound having up to 40 carbon atoms to unreacted Si-H groups.