Objective To observe the role of connective tissue growth factor (CTGF) and collagen synthesis in anti-pulmonary fibrosis (PF) by Kiwi fruit essence(unsaturated fatty acid of actinidia chinesis planch seed oil)in rats. Methods Sixty male SD rats were randomly divided into control group, model group, Kiwi fruit essence (60, 120, 240 mg/kg) treatment groups, and 5 mg/kg prednisone acetate group, with 10 animals in each group. Rats in control group were intratracheally administered with 9 g/L sodium chloride solution, and animals in other groups were intratracheally administered with bleomycin A5 to establish PF model. From the second day on, rats in the latter 4 groups were intragastrically treated with Kiwi fruit essence of 60, 120 and 240 mg/kg and prednisone acetate of 5 mg/kg, respectively. Rats in control and model groups were treated with 9 g/L sodium chloride solution once a day. All rats were sacrificed on day 28, and then pulmonary tissues were removed. The extent of PF lesions were evaluated using HE and Masson staining. The contents of hydroxyproline (HYP) were measured by a commercial kit. The mRNA expressions of CTGF and α-smooth muscle actin (α-SMA) in pulmonary tissues was detected by quantitative real-time PCR. The protein expressions of CTGF, α-SMA, collagen type 1 (Col1) and Col3 were measured by Western blotting. The protein levels of CTGF were analyzed using immunohistochemical staining. Results Compared with the model group, the alveolitis and PF extent in 60, 120, 240 mg/kg Kiwi fruit essence treatment groups as well as 5 mg/kg prednisone acetate group were significantly alleviated, and the content of HYP and the expression of CTGF, α-SMA, Col1 and Col3 decreased. The changes of above indicators were dose-dependent among the (60, 120, 240) mg/kg Kiwi fruit essence treatment groups. Moreover, the above indicators were found higher in (60, 120) mg/kg Kiwi fruit essence treatment groups than those in 5 mg/kg prednisone acetate group, which, however, showed no significantly difference between 240 mg/kg Kiwi fruit essence treatment group and 5 mg/kg prednisone acetate group. Conclusion Kiwi fruit essence down-regulates CTGF expression and decreases the levels of α-SMA, leading to inhibition of Col1 and Col3 synthesis and alleviation of PF.