K2YF5 and K2GdF5 doped with rare earth can be used as thermoluminescent (TL) dosimeters for gamma, beta radiations. In this study, the K2YF5 and K2GdF5 doped with Tb, Pr, Sm, and Dy with different concentrations were synthesized by solid state reaction method. These double fluoride dosimeters were irradiated with different radiations, namely beta and gamma. The study results showed that in general, the TL intensity of K2GdF5 is higher than that of K2YF5. The K2GdF5 crystals doped with Tb3+, Pr3+ have very high TL sensitivities. But the sensitivities of Sm3+, Dy3+ doped- are very low. The TL glow curve of K2YF5:Tb consists of three peaks at temperatures 132oC, 207oC and 240oC, and its intensities are approximately. The TL glow curve of K2GdF5:Tb has dosimetric peak at the temperature 196oC (heating rate 2oC/s), the temperature of this peak suitable for dosimetry application. The TL sensitivity of K2GdF5:Tb is higher than that of TLD-100 and TLD-900 dosimeters for the gamma and beta radiation. The dosimeters K2GdF5:Tb has high sensitivity and linearity for gamma, beta radiations. In addition, the thermal fading effect of TL intensity was very low. The study results showed that these materials can be used in nuclear radiation dosimeters.