Objective · To observe the changes of peripheral and central inflammation in experimental periodontitis rats. Methods · An experimental periodontitis model was established by injecting lipopolysaccharide (LPS) of Porphyromonas gingivalis (P. gingivalis) into the gingival sulcus of SD rats. The pathological changes of periodontal tissue were observed with hematoxylin-eosin staining (H-E staining). The expression of interleukin-1β (IL-1β), IL-6 and IL-8 in peripheral blood, spleen and brain was evaluated by real-time PCR (RT-PCR). Immunohistochemical staining was used to observe the activation of microglia and astrocytes. Differences between groups were compared by using one-way ANOVA, and Tukey test was performed for further comparison between each 2 groups. Results · Sulcus-injection of P. gingivalis-LPS induced periodontitis-like pathologies in rats. Experimental periodontitis could increase the expression of inflammatory factors (IL-1β, IL-6, and IL-8) in the peripheral blood, spleen and brain of rats. Activation of microglial cells and astrocytes was observed in hippocampus of rats. Conclusion · The experimental periodontitis established by P. gingivalis-LPS sulcus injection could induce both peripheral and central inflammation. Inflammation could play an important role in the association between periodontitis and systemic diseases such as Alzheimer's disease.