This study evaluated the effects of low-dose X-ray irradiation treatment on quality characteristics and sensory evaluation of imported navel oranges during storage at 3°C for 45 days. The samples were irradiated at doses of 0.2, 0.4, 0.6, 0.8, and 1.0 kGy, and changes in their color value, hardness, Brix/acid ratio, total sugar content, reducing sugar content, vitamin C contents, and sensory evaluation were investigated. There was no significant increase or decrease in Brix/acid ratio, total sugar content, reducing sugar content, or vitamin C content between the non-irradiated and irradiated samples. Color value of orange peels decreased with increasing levels of irradiation treatment. Color b value of orange pulp increased with an increase in irradiation dose. Difference in hardness between the non-irradiated and irradiated samples decreased at the end of storage. For the sensory evaluation after 30 days, sweetness and overall acceptability of irradiated samples at more than 0.6 kGy were low. These results suggest that X-ray irradiation under 0.6 kGy does not affect quality characteristics and sensory evaluation.