A series of novel Bi3+-doped Ba3Sc4O9 phosphors were synthesized through the solid-state reaction. Their photoluminescence, decay curves, and thermal quenching properties were investigated in detail. The Ba3Sc4O9:Bi3+ phosphors could be efficiently excited in the ultraviolet and near-ultraviolet region (300-400nm), and the photoluminescence properties possess an obvious site-selected excitations phenomenon. When excited at the ultraviolet light (320-360nm), the phosphors present a green or a bluish green emission, and when excited at the near-ultraviolet light (370-390nm), the phosphors always show a yellow emission. The emission spectra excited at the different wavelength can be decomposed into four components, which accord with the four cationic sites in the structure of Ba3Sc4O9. The influence of the Bi3+ concentration on the photoluminescence properties is also investigated. Upon excitation at 330 and 377nm, the Ba3Sc4O9:Bi3+ both have good thermal quenching properties; their emission intensity of the peak at 150 degrees C both exceed 60% of the initial value. The above results indicate that the Ba3Sc4O9:Bi3+ phosphor is a promising candidate to provide green or yellow components for UV or near-UV LEDs.