Objective To observe the effect of Kiwi fruit essence on the expression of connective tissue growth factor (CTGF) protein and mRNA in the lung tissue of rats with radiation-induced lung injury (RILI), and explore whether Kiwi fruit essence can prevent and treat RILI by regulating CTGF. Methods 90 SD rats were divided into blank control group, model group, low dose(60 mg/kg) Kiwi fruit essence group, middle dose (120 mg/kg)Kiwi fruit essence group and high dose(240 mg/kg)Kiwi fruit essence group ，randomly. Except the blank group, the other groups were treated with whole chest radiation to establish the RILI rat model. Seven days before radiation, the low dose group, middle dose group and high dose groups were added with 0.9% sodium chloride according to 60 mg/kg,120 mg/kg and 240mg/kg Kiwi fruit essence, respectively, to form a total 1mL solution, once a day until the rats were killed. The blank group and the model group were given 0.9% sodium chloride 1mL intragastrically at the same time, and 6 rats were randomly killed in each group on the 14th, 28th and 56th day after radiotherapy. Immunohistochemistry, Western blot and qRT-PCR were used to detect the expression of CTGF protein and mRNA.Results Compared with the model group, the degree of alveolitis and pulmonary fibrosis, the score of alveolitis and fibrosis, and the expression of CTGF protein and CTGF mRNA in the 60, 120 and 240 mg/kg of Kiwi fruit essence group were reduced (P＜0.05 or P＜0.01). The changes were more obvious with higher dose (P＜0.05 or P＜0.01).Conclusion Kiwi fruit essence has a protective and therapeutic effect on RILI, and the protective and therapeutic effect is positively related to the concentration of Kiwi fruit essence, and its mechanism may be related to the down-regulation of CTGF expression