Abstract: Macro-dissection, the sinoatrial nodes (SAN) were observed and measured on 95 adult and 30 child cadaver hearts.In adult hearts, most of the SANs were easily identified by their pale colour, hard texture and a tiny nutrient artery at the upper part of the sulcus terminalis, but it was difficult ot recognize the SANs in children.The shape of the apical part of the fight crista auricularis and the notch at the upper part of the sulcus terminalis were observed.A nodal triangle is described for identifying the SAN, and finally, the surface landmarks of the SAN and its connections with myocardial fibers were discussed for clinical application. Applied anatomy of the posterior auricular flap based upon the superficial temporal vessels (p 132)