Abstract: In order to define the effect of precise control of ozone treatment on the quality of raspberries during cold storage, and promote the application of ozone precision control device in the fruits and vegetables postharvest fresh-keeping, the fresh raspberry (variety: Heritage) was processed with short-term fumigation (4 ℃, 1 h, relative humidity of 95%) using the precise ozone refrigerated fumigation device, which was developed by National Engineering and Technology Research Center for Preservation of Agricultural Products. The ozone concentration was set as 0.21, 0.54 and 1.07 mg/L, and the fumigated raspberries were placed in cold store (0 ℃). The ozone fumigation device was tested, and the effects of different concentrations of ozone fumigation treatment on raspberry postharvest storage quality were analyzed. Results showed that using a two-wire ozone transducer installed inside refrigerated cabinet, and through the ozone sensor, the device turned the ozone concentration of refrigerated cabinet into current output to the intelligent measurement and control device, which was then compared with the parameters set on intelligent measurement and control instrument. Thus by relay signal to control the switch of ozone generator, the precise control of ozone concentration was realized. The device could set the concentration in a relatively short time, and accurately control the ozone concentration. The ozone concentrations of 0.21, 0.54 and 1.07 mg/L were respectively acquired after 96, 168, and 240 s since they were set, and the device control precision was 0.05 mg/L. The ozone fumigation treatment could inhibit significantly microorganism of raspberries to flourish (P<0.05), and the total number of colony in raspberries could be reduced by 1.62 orders of magnitude with 1.07 mg/L treatment. The greater the ozone concentration, the smaller the number of colonies, and the ozone concentration and microbial quantity had concentration- response relationship. The color, flavor, hardness, and rotting performance of raspberry with different treatment were good on the 5th day. Raspberry with 0.54 mg/L ozone treatment still had bright red color, fruit tissue without loss, good hardness, and thicker fragrance, but the color, fragrance and hardness of raspberry in control group were poor, and partially rotting of raspberry surface appeared on the 15th day. The raspberry in control group and 1.07 mg/L treatment group had large decay, and the raspberries after 0.54 mg/L ozone fumigation processing still had good performance in color, fragrance and hardness, but individual fruits rotted; there was significant difference between 0.54 and 0.21 mg/L treatment group (P<0.05), and they had extremely significant difference with the control group and 1.07 mg/L treatment group (P<0.01) on the 25th day. For the raspberries treated with 0.21, and 0.54 mg/L ozone fumigation, the degradation of vitamin C, titratable acid, hardness and soluble solids content could be delayed effectively. The 0.54 mg/L ozone fumigation group had the best effect among the treatments. When the ozone concentration was higher than 1.07 mg/L, slight damage appeared on the surface of the raspberry, which promoted the decay of postharvest raspberry, and lowered the nutritional quality, and was not conducive to raspberries storage. In conclusion, precise control of ozone concentration has the potential for making clear the effect of ozone treatment, and controlling the postharvest quality of fruits and vegetables.