目的　了解血清 Ｃ反应蛋白（ Ｃ Ｒ Ｐ） 在老年呼吸系统感染中的意义。方法　采用免疫比浊法测定老年呼吸系统感染患者治疗前后的血清 Ｃ Ｒ Ｐ 水平。结果　治疗前 Ｃ Ｒ Ｐ水平（４５２２ ｍｇ· Ｌ－ １ ±３００５ ｍｇ· Ｌ－ １） 明显高于治疗后（７６５ ｍｇ· Ｌ－ １ ±３２４ ｍｇ· Ｌ－ １ ， Ｐ＜ ００１） ，且其阳性率（８７５ ％ ） 远大于常规指标。结论　血清 Ｃ Ｒ Ｐ 水平是一种反应老年呼吸系统感染的敏感且可靠的指标。 Objective To understand the significance of serum C-reactive protein (C R P) in elderly respiratory infection. Methods The level of serum C R P in elderly patients with respiratory infection before and after treatment was measured by immunoturbidimetry. Results The level of C R P before treatment (4522 mg · L -1 ± 3005 mg · L -1) was significantly higher than that after treatment (765 mg · L -1 ± 324 mg · L -1, P <001), and its positive rate (87  5%) is much larger than the conventional indicators. Conclusions Serum C R P levels are a sensitive and reliable indicator of senile respiratory infections.