Abstract: Objective: To investigate the clinical manifestation and the levels of interleukin-2 (IL-2) , interleukin-12 (IL-12) and monocyte chemotactic protein-1 (MCP-1 ) of SD rats with pneumonia induced by Klebsiella pneumonia and their changes after intervention. Methods: Four to six weeks old SD rats were randomly divided into the model group, control group and intervention group (8 rats each group) . The model and intervention group were inoculated with the same concentration and dose of Klebsiella pneumoniae bacteria, and the control group were inoculated with normal saline. The intervention group were treated with cefoperazone sodium and sulbactam sodium at 24 hours after inoculation. Each group were detected by X-ray through random sample method. The levels of IL-2, IL-12 and MCP-1 of all groups were measured at d3 ，d5 and d7 . results: The levels of IL-2, IL-12 and MCP-1 in model group increased at d3. Compared with the control group, there was significant difference(P ＜ 0. 01) . Compared with intervention group, there was no significant difference(P ＞ 0. 05) . The levels of IL-2, IL-12 and MCP-1 in model group continued to increase at d5 . Compared with the control and intervention group, their differences were statistically significant(P ＜ 0. 01 and P ＜ 0. 05) . The levels of IL-2, IL-12 and MCP-1 in intervention group droped to normal. The levels of IL-2, IL-12 and MCP-1 in model group continued to increase at d7 . Compared with the control and intervention group, their differences had statistical significance(P ＜ 0. 01) . Conclusions: The serum levels of IL-2，IL-12 and MCP-1 increase gradually in the acute infection period of rats with pneumonia induced by Klebsiella pneumonia，which indicates that these factors involve the pathophysiological process of Klebsiella pneumoniae. Dynamic monitoring the serum levels of IL-2, IL-12 and MCP-1 can judge the illness and prognosis of pneumonia induced by Klebsiella pneumonia.