Abstract: Abstract: Aspergillus niger (A. niger) is one of the main dominant pathogens causing the disease of dried ash jujube fruit. Latenting A. niger in the ash jujube produce disease symptoms such as dark spots and rot after infection. Ash jujube had been planted in Xinjiang since the early 1970s and had become one of the leading varieties of Xinjiang jujube industry. After harvesting, most of the Xinjiang ash jujube were dried by natural drying and sent to all parts of the country for sale. Due to improper storage methods, problems such as fungal infection and moth reproduction tend to degrade the quality of fruit, which not only cause a large amount of economic loss, but also endanger human health. Therefore, it is necessary to build a safe and effective method to inhibit the disease of dried ash jujube and maintain quality. Nitric oxide (NO) is a kind of gaseous free radical molecule, which plays an important messenger role in the organism. Numerous studies had shown that exogenous NO treatment significantly delay postharvest senescence of fresh fruits, prolong shelf life and resist infection by pathogenic fungi. In order to provide scientific basis and practical guidance for the application of NO in postharvest dry ash jujube fruit storage and preservation, Xinjiang ash jujube was used as a test material and fumigated by NO gas. The effects of NO fumigation on the inhibition of A. niger disease and the storage quality of dried ash jujube were studied. By in vitro culture and in vivo injury inoculation method, the inhibitory effects of different concentrations of NO on A. niger isolated from ash jujube and A. niger disease were researched. Compared with the control group, NO significantly inhibited the growth of A. niger, and reduced the severity of the fruit disease caused by A. niger. As the concentration of NO increased, the inhibition on A. niger and A. niger disease was more effective. The concentration of 600 μL/L NO completely inhibited the growth and reproduction of A. niger and the occurrence of fruit disease caused by the A. niger, the inhibition rate was 100%. Therefore, the 600 μL/L NO was used to fumigate the jujube fruit for 3 hours which stored at room temperature for 50 days at a temperature of (23 ± 2.0) ℃ and relative humidity 50% ± 5%. The effects of NO fumigation on the occurrence of natural diseases and quality parameters of ash jujube were studied. After storage for 50 days, The NO group decreased the weight loss rate, mold rate, insect rate, browning degree and total number of surface colonies of ash jujube by 0.484%, 1.73%, 3.40%, 0.138 and 1.22 lgCFU/g, respectively; which were significantly lower than that of control group (P<0.05). NO delayed the decrease of moisture, totle soluble solids, reducing sugar, titratable acid and Vitamin C content of the ash jujube, and better maintained the appearance of the fruit. It can be seen that NO fumigation treatment can effectively suppress the A. niger disease in dried ash jujube, and well keep the storage quality of ash jujube fruit. NO has high potential in the control of disease during dried ash jujube storage, which provides a new research idea for NO gas fumigation technology in prevention and inhibition of disease in dried fruits.