[en] An idea for a deformed boson scheme developed by the present authors is applied to the case of boson-pair coherent state. In this state, the even and odd boson number difference is stressed and various concrete examples of boson-pair coherent states are given. Concerning some of them, mutual relations are investigated in connection to the su(1, 1)-algebra. A formulation in terms of the MYT boson mapping is also presented. (author)