  The paper mainly considers the center of two-parameter quantum groups
$U_{r,s}(\mathfrak{so}_{2n+1})$ via an analogue of the Harish-Chandra
homomorphism. In the case when $n$ is odd, the Harish-Chandra homomorphism is
not injective in general. When $n$ is even, the Harish-Chandra homomorphism is
injective and the center of two-parameter quantum groups
$U_{r,s}{(\mathfrak{so}_{2n+1})}$ is described, up to isomorphism.
