Objective: Chronic sialadenitis and Sj(o)grens syndrome are characterized by downregulation of secretory function and hyperexpression ofproinflammatory cytokines, especially tumor necrosis factor-α (TNF-α), while the underlying mechanism of how TNF-α affect salivary secretory function remains unknown.Paracellular pathway plays a critical role in regulating material transport across salivary epithilium,and tight junction forms the primary barrier to solute diffusion through this pathway.The aim of this study was to investigate the secretory regulation mechanism of TNF-α in submandibular gland.