Abstract: Objective To apply the synthesized advanced glycation end products(AGE)to the cultured human gingival fibroblast(HGF)in vitro and then to investigate the effects of AGE on the HGF proliferation and type Ⅰ collagen synthesis and the potential impact of AGE in the repair of periodontium and its molecular mechanism in diabetes-associated periodontitis. Methods The HGF was obtained from explants of human healthy gingival tissues by using tissue-explant technique.The AGE Was prepared and then added to the culture media, its effect on HGF proliferation at different time duration Was examined with MTT colorimetric assay.The type Ⅰ collagen concentrations in cell culture supematants and intracellular proteins were detected by EUSA,and the type Ⅰ collagen mRNA expression of HGF was analyzed by realtime RT-PCR. Results 200 mg/L AGE decreased the A value(P <0.05)and changed the HGF shape.Incubation of HGF with AGE for 72 hours,the quantities of type Ⅰ collagen were reduced(P<0.05),and the expression of type Ⅰ collagen mRNA Was down-regulated(P<0.05). Condusions The AGE inhibited the HGF proliferation,decreased the synthesis of type Ⅰ collagen and down-regulated the expression of type Ⅰ collagen mRNA,impairing the repair of periodontium.