Objective This study aimed to investigate the effects of hirudin on the expression of transforming growth factor (TGF-β1) and basic fibroblast growth factor (bFGF) in human gingival fibroblasts (HGFs) in vitro, as well to explore its function in the mechanism of gingival remodeling.Methods After culturing was performed with classic tissue-explant method, HGFs were derived from normal gingival and gingival hyperplasia tissues followed by orthodontic treatments with different concentrations of hirudin. The mRNA and protein expression levels of TGF-β1 and bFGF were respectively detected by real time quantity polymerase chain reaction and immunocytochemistry.Results Compared with normal HGFs, TGF-β1 expression promoted collagen synthesis of fibroblasts, whereas bFGF collagen synthesis was decreased in hyperplasia HGFs without hirudin (PConclusion Orthodontic force may influence the balance of collagen synthesis and degradation in HGFs. Hirudin may modulate the balance of HGF collagen metabolism, thereby promoting gingival remodeling.