The preservation effect of sea buckthorn leaf extract on sea buckthorn fruits was evaluated. In particular, fresh sea buckthorn fruits were soaked in sea buckthorn leaf extracts of different mass concentrations (5.0, 10.0, 15.0, and 20.0 g•L-1) and stored at 4 ℃ for 9 d, with sterile distilled water as the control. Changes in the appearance, sensory quality, nutritional components, enzyme indexes, and antioxidant indexes of the sea buckthorn fruits during storage were measured. The treatment group with a mass concentration of 15.0 g•L-1 exhibited the best preservation effect throughout the storage period. After 9 d of storage, compared with those in the control group, the color difference value, weight loss rate, decay rate, and malondialdehyde (MDA) content were reduced by 12.92%, 25.46%, 40.62%, and 28.31%, respectively, and the sensory score, soluble solid content, titratable acid content, vitamin C content, and hardness were increased by 21.5%, 11.6%, 13.6%, 68.9%, and 12.7%, respectively. The activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) as well as the scavenging rates of DPPH free radicals and ABTS+ free radicals were 1.83, 1.96, 1.38, 1.51, and 1.15 times those of the control group, respectively. In conclusion, sea buckthorn leaf extract with a mass concentration of 15.0 g•L-1 can effectively delay the quality deterioration of sea buckthorn fruits during storage and prolong their storage period, thus offering high practicality and economic value. These findings provide a theoretical basis for the preservation of sea buckthorn fruits.