【Abstract】Objective To investigate the diagnostic value of really time three-dimensional echocardiography for early detection coronary arterial lesions in children with atypical Kawasaki disease. Methods Both 2D-ECHO and RT-3DE were used to examine 20 patients who were confirmed by CTA. The image’s quality and the reliability of the diagnosis of 2D-ECHO and RT-3DE were compared. Results 1) The quality of the 2D-ECHO images is a little better than that of RT-3DE.2) The accuracy of CTA and RT-3DE in the diagnosis of coronary artery lesions is consistent. Conclusions RT-3DE is a good diagnostic tools to detect coronary arterial lesions in patients with atypical Kawasaki disease, RT-3DE could confirm or correct some diagnosis of 2D-ECHO. Therefore, combining the 2D-ECHO and RT-3DE has practical clinical value in atypical Kawasaki disease.