The effects of the type and concentration of alkaline-earth metal ions are systemically investigated on removing OH groups of erbium-doped phosphate glasses, by using fluoresent lifetime of erbium-doped phosphate glasses varying with OH concentration. The experimental results indicate that bubbling dry O2 and CCl4 gases into glasses could effectively reduce OH groups. The OH groups were removed rapidly at the beginning, then slowed down with increasing bubbling time, and finally, the removing and absorbing of OH groups of erbium-doped phosphate glasses reached equilibrium. It should be mentioned here that the fluorescence lifetimes at the same bubbling time decrease with increasing alkali-earth ions radius in the order of Ca>Sr>Ba. The erbium-doped phosphate glasses which have a high alkaline-earth metal ions concentration, exhibit a short fluorescence lifetime and a strong reabsorbing ability of OH- groups after stopping bubbling gas.