Abstract: In order to investigate the influence of X-ray irradiation dose on the germination and storage quality of coloured potatoes, this study took the coloured potatoes Yellow Rose 3, Purple Rose 3, Red Rose 5 and common potatoes as test materials, and treated them with 5 MeV electron-beam rotary target X-rays at 0, 100, 300 and 500 Gy. The treated potatoes were stored at room temperature (20±2) ℃ with a relative humidity of 80%~90%. In order to study the influence of X-ray irradiation on the appearance, nutritional quality and fresh-keeping effects of potatoes, parameter changes of germination rate, weight loss rate, hardness, V_C content, dry matter content and respiration intensity during the storage period were analyzed. The results showed that X-ray irradiation treatment reduced the respiratory intensity of potatoes in the mid to late storage period and decreased the weight loss, hardness decline and loss of V_C content during storage. Compared with control group, 100 Gy irradiation treated Yellow Rose 3, Purple Rose 3, Red Rose 5 and common potatoes reduced the weight loss rate by 12.76%, 5.31%, 6.05% and 1.43%, respectively, the degree of decrease in hardness at the end of the storage period compared with the beginning of storage period was reduced by 12.98%, 6.40%, 8.34% and 7.13%, respectively, and the rate of loss of V_C content was reduced by 17.71%, 22.80%, 13.52% and 14.65%, respectively. Four varieties of potatoes did not sprout even after storage for more than 240 days after receiving different doses of X-rays. A low dose of 100 Gy of X-ray irradiation treatment could achieve an optimal sprout inhibition effect. Moreover, it delayed weight loss and hardness decline more effectively than 300 and 500 Gy. This dose could be recommended as the dose for irradiation preservation of coloured and ordinary potatoes in industrial applications. This research provides a theoretical basis and technical guidance for the application of X-ray irradiation technology in the storage and preservation of coloured potatoes.