Objective To investigate the clinical value of Tei index in the myocardial function in patients with Kawasaki disease(KD). Methods In the prospective study, 50 patients underwent echocardiogramphic evaluation. The left ventricular ejection fraction (EF), shortening fraction (FS), peak E/A ratio at mitral valve (E/A), peak S/D ratio of pulmonary venous flow (S/D), isovolumetric continuaction time (ICT), isovolumetric relaxation time (IRT) and ejection time (ET) were measured. Tei index was calculated. As a control, we also assessed 72 healthy children, matched for age and sex with the study population. Results Compared with the control group, left ventricular Tei index was significantly increased in the children with acute KD guoup (0.44±0.07 vs 0.37±0.05,P＜0.01). Tei index of KD group in convalescent stage was decreased (0.40±0.09 vs 0.37±0.05, P>0.05). Right ventricular Tei index was also significantly increased in the children with acute KD guoup (0.44±0.07 vs 0.37±0.05,P＜0.01) compared with the healthy children. And during the convalescent stage, the right ventricular Tei index tended to normal. Conclusions The ventricular global function was impaired in children with acute KD. Tei index is a accurate and sensitive tool for estimating global myocardial dysfunction in KD patients.