Objective To assess ①the effect of signal transducer and activator of transcription (STAT) on pulmonary injury induced by cecal ligation puncture (CLP) in septic rats; ②the biological effect of interleukin (IL)-6 and IL-10 expression in pulmonary injury mediated by STAT in septic rats. Methods Sepsis of rats was induced by CLP. Male Wistar rats were randomly divided into normal control (n=8), CLP group (n=24), and inhibitor (rapamycin, RPM) of STAT pretreatment group (n=24). At serial time points in each group, animals were sacrificed. Then, pulmonary tissue and serum samples were harvested to determine IL-6 and IL-10 mRNA expression by reverse transcription polymerase chain reaction (RT-PCR) and protein expression levels by enzyme-linked immunosorbent assay (ELISA). Meanwhile, pulmonary STAT-1 DNA-binding activity was detected by electrophoretic mobility shift assay (EMSA) . Activity of myeloperoxidase (MPO) as well as histopathology were also evaluated. Results Compared to normal control, pulmonary STAT-1 activity at 6 h, 24 h and 48 h following CLP significantly elevated (P