An amino compound having a secondary amino group directly bonded to a phenyl group is modified by silylating the secondary amino group. When the silylated amino compound is compounded in a silicone composition comprising an organopolysiloxane containing at least two lower alkenyl groups, an organohydrogenpolysiloxane, and a platinum base curing catalyst, the composition is improved in flame retardance to the level of UL-94 V-0 without sacrificing the activity of the curing catalyst.