To discuss the therapeutic advantages and mechanism of Ertian decoction by the comparative study of Ertian decoction and Huai Qi Huang Granule on prevention and treatment of primary nephrotic syndrome(PNS)at remission stage with both qi and yin deficiency which occurs to children.Methods:The test was performed by group contrast，80 cases in accordance with the inclusion criteria were divided into the treatment group and the control group，40 cases in each.In the treatment group，trial subjects were treated with glucocorticoid as the main drug combined with traditional Chinese medicine “Ertian Decoction”.In the control group，the main drug glucocorticoid with Huai Qi Huang granules were used.The treatment in both groups lasted for 8 weeks.The symptom integral，clinical efficacy and recurrence rate in six months of two groups were observed and collected.Results:1)Comparing the symptom integral with before，the data difference has statistics significance(P<0.05)，the integral of treatment group was significant lower than that of the control group(P<0.05);2)Comparing the total effective rate of TCM symptom effect between the 2 groups，the treatment group total effective rate was 94.7%; the control group total effective rate was 81.0%，P<0.05，statistically significant difference reveals that the treatment in treatment group was more effective than that of the control group;(3)Following up the trial subjects for six months，the recurrence rate of the treatment group was 21% while the control group was 29.7%，the recurrence rate of the treatment group was lower than the control group，P<0.05，there was statistically significant difference.Conclusion:Ertian Decoction is superior than Huai Qi Huang granules in treating children who have PNS in remission with qi and yin deficiency to improving symptoms and other aspects.Besides，it can reduce side effects of hormones effectively and prevent relapse of kidney disease.It is more safe to use.There’s a good clinical value for the prevention and treatment of PNS.