The Change in interleukin-2 (IL-2) production of splenocyte and its relationship with suppressor T cell (Ts) were studied in mice after trauma. The results showed that IL-2 production was reduced, number of Ts was increased and activity of Ts correlated with reduced IL-2 production. Removal of Ts from splenocyte improved IL-2 production in traumatized mice. It is suggested that Ts is activated after trauma, resulting in impaired IL-2 production.