We investigated the persistent luminescence in europium-doped barium chloroapatite upon codoping with auxiliary rare earth ions. Luminescence properties of the phosphors, including photoluminescence, luminescence decay, and thermoluminescence are systematically studied. We formulated a model of persistent luminescence on the basis of the experimental results. In our model, some Eu2+ ions are oxidized to Eu3+ under short UV excitation, and the released electrons are trapped at the positive defect. The persistent luminescence arises from the recombination of these trapped electrons with the photo-ionized Eu3+ ions. The influence of auxiliary codopants was discussed in terms of ionic potential and ionic radius. Eventually, the concentration quenching of persistent luminescence was reported and discussed. (C) 2013 Elsevier Ltd. All rights reserved.