Monovalent ions Li+, Na+, and K+, as charge compensators, are introduced into CaYAl3O7: M (M=Eu3+, Ce3+) in this letter. Their crystal phases and photoluminescence properties of different alkali metal ions doped in CaYAl3O7 are investigated. In addition, the influence of charge compensation ion Li+ which has a more obvious role in improving luminescence intensity on CaYAl3O7: Eu3+ phosphor is intentionally discussed in detail and a possible mechanism of charge compensation is given. The enhancement of red emission centered at 618 nm belonging to Eu3+ is achieved by adding alkali metal ion Li+ under 393-nm excitation.