Objective To study the regulation of PHF14 expression in the process of acute kidney injury (AKI) and renal fibrosis, so as to evaluate the role of PHF14 in the renal fibrosis after AKI. Methods Twenty adult C57BL/6 mice were randomly divided into two groups:vehicle group (n=5) and folic acid group (n=15). Mice were given intraperitoneal injection of vehicle (0.3 mol/L NaHCO₃ solution) alone (control group) or together with folic acid (folic acid group) at the dose of 250 mg/kg. Mice in folic acid group were further divided into three subgroups according to the length of follow-up (2 day, 14 day and 28 day, respectively). Mice were sacrificed at the planned time points and the kidney tissues and blood samples were collected for evaluating the renal function and the renal fibrosis parameters; Masson's trichrome staining was used to verify AKI model; and Western blotting analysis was used to study the expression profile of PHF14. After the verification of renal fibrosis model, the induced PHF14 knockout mice and wild type mice were given folic acid or vehicle and were studied following the same protocol mentioned above. Western blotting analysis was performed to examine the expression profile of transforming growth factor β (TGF-β),α-smooth muscle actin (α-SMA) and collagen 1 at the predesigned time points. Immunohistochemical staining was performed with anti-α-SMA and anti-collagen 1 antibodies. Results The folic acid nephropathy model was verified by serum creatinine (SCr), blood urine nitrogen (BUN) and renal fibrosis morphologic analysis in folic acid group. Pathological changes of the kidney showed gradual renal fibrosis with the increase of folic acid exposure time, indicating the successful establishment of AKI model. PHF14 expression was elevated persistently during the process of fibrogenesis after folic acid-induced injury. Compared with wild type mice, Western blotting analysis and immunohistochemical staining showed that PHF14 knockout mice had higher expression of TGF-β, α-SMA and collagen 1. PHF14 knockout significantly exacerbated the interstitial inflammation and fibrosis in renal tissue in mice. Conclusion Intraperitoneal folic acid injection can create AKI and renal fibrosis in mice. PHF14 expression is persistently elevated after the pro-fibrotic insults. Knock-out of PHF14 gene can exacerbate the renal fibrosis following AKI, indicating that PHF14 might be a protective factor of renal fibrosis.