This paper reports the luminescence emission spectra of YTaO₄ activated by Eu³ and Tb³ rare earth ions. The influence of these rare earth ions on the luminescence of yttrium tantalate phosphors was investigated. The luminescent properties were studied under X-ray and electron beam excitations. Under these excitations, the emission centers of the rare earth activators (Eu³, Tb³) were found to contribute efficiently to the overall luminescence. Color cathodoluminescence images showed clearly the dependence of chromaticity on different activators. With their various luminescence chromaticities, these rare earth activated phosphors are promising materials for optoelectronics applications as well as for X-ray intensifying screens in medical diagnosis, providing the broad variation of visible photoluminescence from blue to red.