Employing the first principles discrete variational method(DVM), we investigated the electronic structure of LaNi5 hydrogen storage alloys containing various alloying elements, M=Mn,Fe,Co. The results showed that s electrons of H mainly interact with s electrons of hydride-non-forming element Ni, though hydride forming element La have stronger affinity to hydrogen atom. And alloying elements strengthened the bond between B-H, so decreased the capacity of doped-system.