Objective To explore the clinical significance of changes on serum IL-2, IL-10 and beta-defensin-2 levels both before and after treatment in patients with aggressive periodontitis. Msthods Serum IL-2, IL-10 (with RIA) and beta-defensin-2 (with ELISA) levels wece determined in 40 patients with aggressive periodontitis and 35 normal healthy controls. RosultS Before treatment, serum IL-2 and beta-defensin-2 levels were significantly lower than those in controls (P<0.01). But serum IL-10 leveb were markedly higher than that of controls (P <0.01). After treatment for 3 months, the levels changed notably by toward normal, but remained significant difference from the controls (P<0.05). Conclusion Decreased serum IL-2, beta-defensin-2 and increased IL-10 was found after aggressive periodontitis may be uniquely of risk factor.