The study focused on the measurement of percentage depth dose (PDD) in high energy photons and electrons by using the optically stimulated luminescent (OSL) dosimeters. The beam output calibration was performed on 6 MV photons and 6 MeV electrons and compared to that in the ionization chamber. The PDD was measured in 6 MV photons and 6 MeV electrons and the PDD curves were plotted by using the OSL dosimeters. The PDD curves were compared to that in other common dosimeters including ionization chamber, Gafchromic® EBT2 film dosimeter and the treatment planning software (TPS). The results showed that the beam output calibration measured by using the OSL dosimeters was in good agreement to the ionization chamber within 1.6 and 5.9% percentage of discrepancy for both 6 MV photons and 6 MeV electrons respectively. The measured PDD by using the OSL dosimeters were also in in good agreement to the ionization chamber, EBT2 film and TPS software within percentage 13.4 and 10.4% of discrepancies for 6 MV photons and 6 MeV electrons respectively. The overall results indicated the suitability of OSL dosimeters to be used for direct dosimetry measurements in high energy photons and electrons.