an organosilicon compound represented by the general formula : ## str1 ## wherein rf represents a perfluoroalkyl group or a perfluoroalkyl ether group ; r 1 may be the same or different and each represent a monovalent hydrocarbon group ; r 2 represents an alkylene group ; r 3 represents a hydrogen atom or a monovalent hydrocarbon group ; and a is an integer of 1 to 4 , b is an integer of 1 to 3 and c is an integer of 0 to 3 , provided that a , b and c satisfy the relationship of 3 ≦ a + b + c ≦ 6 ; is provided . these organosilicon compounds are novel compounds useful as crosslinking agents for addition - curable silicone rubber compositions .