UV-A irradiation of Gafchromic XR-RV3 and XR-SP2 are considered to be a substitute for X-ray irradiation in the double irradiation of Gafchromic XR-RV3 and XR-SP2. It makes it possible to compensate for heterogeneity errors in the active layers of Gafchromic XR-RV3 and XR-SP2. UV-A with a wavelength of 395-nm was irradiated to Gafchromic XR-RV3 and XR-SP2, and irradiation time and color density change were investigated. At first, Gafchromic XR-RV3 and XR-SP2 were pre-irradiated for 2 and 4 hours, respectively, by UV-A with a wavelength of 365-nm, with UV-A fluorescent lamp as the radiation source, located at a distance of 72 cm. Secondly, a UV-A light emitting diode (LED) capable of generating 395-nm UV-A was used. The irradiation times of UV-A for Gafchromic XR-RV3 and XR-SP2 were from 5 to 120 minutes and from 30 to 300 minutes at a distance of 5.0 cm, respectively. From these results, appropriate irradiation time was considered. A 0.5 inchs diameter region of interest was set for each irradiation area, and a histogram of pixel values was obtained. The selected condition was two items "There is not 0 in a mode", "A 1/10 level intersects both sleeves of graph". When Gafchromic XR-RV3 and XR-SP2 were irradiated with ultraviolet rays of wavelength 395 nm as an X-ray substitute for double irradiation technology, it was proved that 60 minutes (5511.00 mJ/cm2) and 270 minutes (24799.50 mJ/ cm2) were sufficient for irradiation time respectively. And both distance was 5cm.