In this paper we present an study on the EPR and photoluminiscence spectra of Gd3+in the mixed crystals Ca0.998-xRxGd0.002F0.002+x(x≤0.35, R=La or Y). For x <0.1 the EPR spectrum shows a main signal due to cubic Gd3+that is broadened as x increases. Different broadenings are found for La and Y samples For high x values the EPR spectrum is similar to that in glass matrices. The results are explained taking to account a random second rank crystal field due to the extra charges associated with R3+and fluorine intersitials. The6P→6S emission of Gd3+also has been measured. The influence of R concentration on this luminiscence has been studied.