The possibilities of B′ meson mixing is discussed. It is found that if fB′ is not much smaller than fπ, B's (or B'd) mixing is possible if |Vt′s Vt′b′/Vcb′| is large, but only for not too heavy b′ masses, e.g. below LEP I energies. The B'b meson will have large mixing for a broad range of parameters; however, it is hard to produce. The vector mesons (B′*) may exhibit mixing phenomena as well. A discussion of our present understanding of meson decay constants of a heavy-light system [Formula: see text] is given. Further efforts on this problem is needed, which will have an impact on our understanding of B mixing as well.