目的　探讨急性感染性腹泻患儿血清一氧化氮 (NO)和免疫球蛋白 (Ig)水平的变化及相互关系。方法　分别采用硝酸还原酶法及透射比浊法对 5 6例急性感染性腹泻患儿及 2 0例正常健康儿童进行了血清NO和IgG、IgA、IgM水平的测定。结果　急性感染性腹泻患儿急性期血清NO水平明显高于恢复期及正常对照组 ,且NO水平与病情的危重程度有关 ;急性感染性腹泻患儿急性期血清IgG、IgA、IgM水平较恢复期及正常对照组均明显降低 ;且感染性腹泻的IgG、IgA水平与病情的严重有关 ;急性感染性腹泻患儿急性期血清NO与IgG、IgA、IgM水平均呈显著负相关关系。 结论　血清NO、IgG、IgA、IgM与小儿急性感染性腹泻的发生发展密切相关 Objective To investigate the changes and correlations of serum nitric oxide (NO) and immunoglobulin (Ig) levels in children with acute infectious diarrhea. Methods Serum NO, IgG, IgA and IgM levels were measured in 56 children with acute infectious diarrhea and 20 normal healthy children respectively by nitrate reductase method and turbidimetric method. Results The serum level of NO in patients with acute infectious diarrhea in acute stage was significantly higher than that in recovery stage and normal control group, and the level of NO was related to the severity of the disease. The serum levels of IgG, IgA and IgM in acute infectious diarrhea children were higher than those in recovery stage And normal control group were significantly lower; and infectious diarrhea, IgG and IgA levels and severity of the disease; acute infectious diarrhea in children with acute serum NO and IgG, IgA, IgM levels showed a significant negative correlation. Conclusion Serum NO, IgG, IgA and IgM are closely related to the occurrence and development of acute infectious diarrhea in children