Photoconductivity of rare earth doped mixed bases of II-VI compounds has not drawn any particular attention, although formation of mixed bases is important from the point of view of extending the maximum response in the visible region. With this in mind, the photoconductivity of (CdSe,ZnS):La has been investigated. The lower values of photocurrent at lower and higher concentrations of lanthanum may be due to a release of fewer electrons from lanthanum and concentration quenching, respectively. Two trap depths at 0. 54 and 0. 45 eV have been found and these depend on the concentration of lanthanum.