Objective To investigate the expressions and clinical significance of anti-β1--adrenoceptor antibody (β1AA) and connective tissue growth factor(CTGF) in peripheral blood of children with dilated cardiomyopathy (DCM).Methods Twenty-seven patients diagnosed as DCM hospitalized in Department of Pediatric Cardiology,Shandong Provincial Hospital Affiliated to Shandong University from October 2015 to April 2016 were selected to be the DCM group.And 20 healthy subjects were chosen as the healthy control group.The patients in the DCM group were scored according to modified Ross score as the referential criteria.The left ventricular end-diastolic diameter (LVEDD) and left ventricular ejection fraction (LVEF) of all the children were measured by using cardiac ultrasound.Enzyme-linked immunosorbent assay was used to determine the levels of β1 AA,CTGF,high-sensitivity troponin T (hs-TnT)and N-terminal pro-brain natriuretic peptide (NT-proBNP) in the serum of all the children.Results (1) There was no statistically significant difference between the 2 groups in gender and age (all P ＞ 0.05).(2) Compared with the healthy control group,the β1AA level,CTGF level and LVEDD in the DCM group significantly increased [(260.23±34.03) ng/L,(1 223.44±190.85) ng/L,(53.02 ±11.01) mmvs.(224.80±34.90) ng/L,(937.16 ± 114.50) ng/L,(32.51 ±5.95) mmn],while the LVEF value significantly decreased[(28.15 ±7.34)％ vs.(64.15 ±0.88) ％],and the differences were statistically significant (t =-3.49,-5.95,-7.54,21.74,all P ＜ O.01).(3)Compared with DCM children of normal hs-TnT level,β1 AA level and CTGF level in DCM children of abnormal hs TnT level significantly increased[(269.56 ± 34.78) ng/L,(1 276.88 ± 189.38) ng/L vs.(233.56 ± 8.30) ng/L,(1 070.76 ± 86.87) ng/L],and the differences were significant (t =-2.68,-2.75,all P ＜ 0.05).(4) The β1AA level and CTGF level had no statistically significant difference between different gender groups in DCM children (all P ＞0.05).(5)In the DCM group,the level of β1AA was positively correlated with the level of NT-proBNP and modified Ross score(r =0.745,0.813,all P ＜ 0.01),but negatively correlated with LVEF (r =-0.646,P ＜ 0.01),andnot correlated with age (P ＞ 0.05).In the DCM group,the level of CTGF was positively correlated with the level of NT-proBNP and modified Ross score (r =0.798,0.823,all P ＜ 0.01),negatively correlated with LVEF (r =-O.642,P ＜ 0.01),and not correlated with age (P ＞ 0.05).Conclusions The β1 AA and CTGF significantly increased in DCM children,and were related to hs-TnT level,NT-proBNP level,modified Ross score and LVEF value.They represent the severity of the disease and can be used as new reference indicators to assess the condition of children with DCM.