To find out the relationship between nitric oxide and onset of infantile acute nephritis, and the effect of traditional Chinese medicine (TCM) and Western medicine (WM) combination therapy. Methods: Dividing 44 infantile acute nephritis patients into two groups. Group 1 was treated with cooling blood and diuretic principle, together with WM, Group 2 was treated with antipyretic and detoxication, cooling blood and diuretic principle, together with WM. The content of ferrous nitrite/nitrate (Fe NO 2/NO 3) in blood before and after treatment were determined through Griess nitrate reduction method, then compared with that of 28 healthy children. Results: The content of Fe NO 2/NO 3 being in acute nephritis period was obviously higher than that of the control group and convalescent period, P <0 01. The macroscopic hematuria was higher than that of microscopic one, P <0 01. Urinary alexin 3 element (C 3) and α 2 macroglobulin positive patients Fe NO 2/NO 3 was higher than that of negative ones, P<0 01. Those complicated with infection Fe NO 2/NO 3 was higher than that without infection P<0 01. Short term cure rate of group 2 was higher than that of group 1, P<0 05. Nitric oxide may participate the onset and pathogenesis of infantile acute nephritis. Conclusion: TCM WM combination therapy, especially antipyretic and detoxication, cooling blood and diuretic principle, could restrain nitric oxide from damaging tissue and remitting disease. To find out the relationship between nitric oxide and onset of infantile acute nephritis, and the effect of traditional Chinese medicine (TCM) and Western medicine (WM) combination therapy. Methods: Dividing 44 infantile acute nephritis patients into two groups. Group 1 was treated with cooling blood and diuretic principle, together with WM, Group 2 was treated with antipyretic and detoxication, cooling blood and diuretic principle, together with WM. The content of ferrous nitrite / nitrate (Fe NO 2 / NO 3) in blood before and after treatment were determined through Griess nitrate reduction method, then compared with that of 28 healthy children. Results: The content of Fe NO 2 / NO 3 being in acute nephritis period was obviously higher than that of the control group and convalescent period, P <0 01. The macroscopic hematuria was higher than that of microscopic one, P <0.01. Urinary alexin 3 element (C 3) and α 2 macroglobulin positive patients Fe NO 2 / NO 3 was higher than that of negative ones, P <0 01. Those complicated with infection Fe NO 2 / NO 3 was higher than that without infection P <0 01. Short term cure rate of group 2 was higher than that of group 1, P <0 05 . Nitric oxide may participate in the onset and pathogenesis of infantile acute nephritis. Conclusion: TCM WM combination therapy, especially antipyretic and detoxication, cooling blood and diuretic principle, could restrain nitric oxide from damaging tissue and remitting disease.