The Ca2SiO4:Dy3+ phosphor was synthesized by high temperature solid-state method. The emission spectrum of Ca2SiO4:Dy3+ shows bands at 486nm，575nm and 665nm under the 365nm excitation. The excitation spectrum for 575nm emission has excitation bands at 331nm，361nm，371nm，397nm，435nm，461nm and 478nm. The effect of Dy3+ concentration on the emission spectrum and luminescent intensity of Ca2SiO4:Dy3+ was investigated.The result shows that the ratio (Y/B)of yellow emission (575nm)to blue emission (486nm)increases with increasing Dy3+ concentration，and the reason was explained by Judd-Offelt theory. The luminescent intensity firstly increases with the increasing Dy3+ concentration，then decreases，and the concentration self-quenching mechanisms are the d-d interaction according to the Dexter theory. The effect of Li+，Na+ and K+ on the emission spectra of Ca2SiO4:Dy3+ phosphor was studied. The results show that the emission spectrum intensity of Ca2SiO4:Dy3+ phosphor is greatly influenced by Li+，Na+ and K+，and the evolvement trend is the same for different charge compensations，i.e.，the emission spectrum intensity firstly increases with increasing charge compensation concentration，then decreases. However, the charge compensation concentration corresponding to the maximum emission intensity is different for different charge compensations，and the concentrations are 4，4 and 3 mol% for the Li+，Na+ and K+，respectively.