Objective This study aimed to reveal the effect of α-linolenic acid on airway inflammation and fibroblast growth factor 23 (FGF23) expression in rats model of asthma. Methods In this study, an ovalbumin (OVA)-induced asthma SD rat model was established, and the rats were randomly divided into 5 groups (n=10): control group, OVA group (asthma model rats), OVA+ 40 mg/kg ALA group (asthmatic model rats treated with 40 mg/kg α-linolenic acid), OVA+80 mg/kg ALA group (asthmatic model rats treated with 80 mg/kg α-linolenic acid) and OVA+Dex group (asthmatic model rats treated with 0.25 mg/kg dexamethasone). The rats were treated continuously for 7 days. Lung tissue morphology was evaluated by HE staining. The levels of interferon-γ (IFN-γ), interleukin (IL)-4, IL-17 and IL-10 in bronchoalveolar lavage fluid (BALF) were detected by ELISA. Serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) and high-density lipoprotein (HDL) were detected by automatic biochemical analyzer. The expressions of FGF23, FGFR4, Klotho, E-cadherin and α-SMA in lung tissue were detected by immunohistochemistry, Western blot or qRT-PCR. Results Compared with OVA group, OVA+40 mg/kg ALA group, OVA+80 mg/kg ALA group and OVA+Dex group rats had significantly reduced lung lesions. Compared with OVA group, the levels of IFN-γ and IL-10 in the BALF of OVA+40 mg/kg ALA group, OVA+80 mg/kg ALA group and OVA+Dex group were increased, while the levels of IL-4 and IL-17 decreased (P<0.05). Compared with OVA group, the serum levels of TC, TG and LDL in OVA+40 mg/kg ALA group, OVA+80 mg/kg ALA group and OVA+Dex group were decreased, while HDL was increased (P<0.05). Compared with OVA group, the protein expression level of E-cadherin in the lung tissue of OVA+40 mg/kg ALA group, OVA+80 mg/kg ALA group and OVA+Dex group increased, while α-SMA decreased (P< 0.05). Compared with OVA group, the mRNA and protein expression levels of FGF23 and FGFR4 in the lung tissue of OVA+40 mg/kg ALA group, OVA+80 mg/kg ALA group and OVA+Dex group were decreased, while Klotho level was increased (P<0.05). Conclusion Alpha-linolenic acid can inhibit airway inflammation and epithelial-mesenchymal transition and improve lipid metabolism in asthmatic rats, and the mechanism may be achieved by correcting the imbalance of Th1/Th2 and Treg/Th17 and regulating FGF23-Klotho-FGFR4 signaling