Let Gn(C) be the sandwich semigroup of generalized circulant Boolean matrices with the sandwich matrix C and GC(Jn) the set of all primitive matrices in Gn(C).In this paper,some necessary and sufcient conditions for A in the semigroup Gn(C) to be primitive are given.We also show that GC(Jn) is a subsemigroup of Gn(C).