Abstract: Objective To investigate the changes in the concentration of myocardin in children with lupus nephritis (LN) under different degree of vessel damage. Methods Forty-nine children diagnosed with LN by routine tissue immunofluorescence, light microscope, and electron microscope were included, and 30 healthy children were included as control group. The pathological classifications were performed according to the ISN/RPS 2003 LN pathological classification criterion. According to the Katafuchi evaluation method, the semi quantitative assessment of glomerular and kidney tubule damage was carried out, and the degree of vascular damage was evaluated at the same time. Double antibody sandwich method was used to detect the concentration of serum myocardin. Results The glomerular and kidney tubules damage in children with LN were significantly aggravated with higher pathological classification (P ＜ 0.05). Glomerular damage was positively correlated with renal interstitial damage (r =0.96, P ＜ 0.01). The degree of vascular damage was related to the degree of glomerular injury and renal interstitial injury, while it was no related with the results of clinical tests. There were different concentrations of myocardin among mild-, moderate-, severe-vessel damage and control groups (F =378.61, P ＜ 0.001), and the concentration of myocardin in moderate- and severe-vessel damage groups were obviously lower than those in control group and mild-vessel damage group (P ＜ 0.01) while there was no difference between control group and mild-vessel damage group (P ＞ 0.05). According to pathological type, there were significant differences in the concentration of myocardial between control group and different pathological types (F =626.793, P ＜ 0.01). From Ⅱ, Ⅲ, Ⅲ+Ⅴ,Ⅳ to Ⅳ+Ⅴ, the concentrations of myocardial were decreased systematically, and there were statistic differences between groups (P all ＜ 0.05). Conclusion The concentration of myocardin in children with LN can reflect the renal vascular damage to a certain extent. Elevation of myocardin concentration may be helpful for the repair of vascular damage.