目的　探讨儿童胸腔积液病因及诊断线索。 方法　收集1994年1月至2014年1月入院时伴有胸腔积液的患儿2 419例，采集临床资料，并分成感染性和非感染性两组进行回顾性分析。结果　2 419例患儿中男1 523例、女896例，平均年龄(6.5±4.0)岁，其中感染组2 353例、非感染组66例。感染组较非感染组更易伴有发热，呼吸困难和中到大量积液的发生率低于非感染组(P均<0.01)。感染组中，不同类型感染性胸腔积液的年龄分布差异有统计学意义(P<0.01)，肺吸虫性胸膜炎集中分布于3~7岁(64.0%)，结核性胸膜炎在>7岁发生率较高(53.6%)，而脓胸则好发于≤3岁(51.4%)。感染组的预后明显好于非感染组(P<0.01)。结论　儿童胸腔积液以感染为主，病因诊断时需综合考虑发病率、临床表现、积液量等线索，鉴别感染性与非感染性胸腔积液。

Objective　To investigate the etiology and diagnostic clues of childhood pleural effusion. Methods Two thousand four hundred and nineteen hospitalized cases of pleural effusion from Jan. 1994 to Jan. 2014 were included and divided into infection group and non-infection group. Then the clinical data were collected. Results There were 1523 males (63.0%) and 896 females with an average age of 6.5±4.0 years old. There were 2353 cases in the infection group and 66 cases in the non-infection group. The incidence of fever in infection group was much higher than that in non-infection group, whereas the incidence of dyspnea and moderate-to-large pleural effusion was lower (all P<0.01). There was a significant difference of age distribution among children with different infectious pleural effusion. In infection group, the paragonimus szechuanensis pleurisy occurred preferentially in children 3-7 years old, the tuberculous pleurisy occurred preferentially in children >7 years old and the purulent pleurisy occurred preferentially in children ≤ 3 years old. The prognosis of infection group was much better than that of non-infection group (P<0.01). Conclusions Infection is the predominant cause of childhood pleural effusion. The differential diagnosis from non-infectious pleural effusion should consider the incidence, clinical manifestations and effusion quantity.