Objective To investigate the changes of serum creatine kinase (CK),creatine kinase isoenzyme (CK-MB),cardiac troponin I(cTnI)and electrocardiogram (ECG) before and after the treatment of pneumo-nia in children.Methods From December 2014 to December 2016,95 children with pneumonia were selected as the study group,and 48 healthy subjects who underwent the healthy assessment from December 2014 to January 2016 were selected as the control group.All children with pneumonia were treated after admission.2 mL of venous blood were collected from each research subject after the admission and patients in study group after treatment,serum was seperated,and levels of CK,CK-MB,cTnI were measured and the ECG record was conducted.Results The serum levels of CK,CK-MB and cTnI in the study group were higher than those in the control group (P<0.05);the incidences of ST segment elevation or depression,atrial premature beat,ven-tricular premature beat,sinus tachycardia and sinus bradycardia in the study group were higher than those in the control group,and the differences were statistically significant (P<0.05);the serum levels of CK,CK-MB and cTnI in the study group were lower than those before treatment,and the difference was statistically signif-icant (P<0.05);the incidences of atrial premature beat,ventricular premature beat,sinus tachycardia and si-nus bradycardia in the study group after treatment were lower than those before treatment,and the difference was statistically significant (P<0.05);the incidence of ST segment elevation or depression after treatment in the study group was lower than that before treatment,and there was no significant difference (P>0.05).Con-clusion The serum levels of CK,CK-MB,cTnI and ECG were obviously abnormal in children with pneumoni-a.After treatment,serum CK,CK-MB and cTnI levels can be reduced and ECG abnormalities can be ameliora-ted.