In this article, we investigated changes of immune functions and immunoregulatory effects of indomethacin on rats with trauma. The results show that spontaneous suppressor T cell activity of spleen significantly increased and Interleukin I production and DNA synthesis capacity of splenocytes markedly decreased in rats with trauma. Indomethacin could markedly improve immune function, decreased spontaneous suppressor T cell activity and prompted Interleukin 2 production and DNA synthesis capacity of splenocytes.