Objective: To explore the electrocardiographic characteristics of patients with idiopathic ventricular arrhythmias (VAs) originating from different portions of distal great cardiac veins (DGCV). Methods: The study included 49 patients underwent successful RFCA of premature ventricular complex(PVCs)/ventricular tachycardia(VT) from different portions of the DGCV in our department from July 2009 to March 2016. The surface 12-lead electrocardiogram (ECG) and intraventricular ablation mapping features were analyzed. Patients were divided into four groups according to the mapping and ablation results: DGCV1(10 patients), DGCV2 (13 patients), proximalanterior interventricular vein (PAIV, 17 patients)and extend distal great cardiac vein (EDGCV, 9 patients). We analyzed the similarities and differences between surface 12-lead ECG of patients with PVCs/VT from different portions of DGCV, and compared with random chosen 290 patients with PVCs/VT from ventricular outflow tract and adjacent structure. Results: A positive R wave in inferior leads, a negative QS morphology in lead aVL and aVR were found among all groups. The different characteristics of surface 12-lead ECG of VAs originating from DGCV were as follows: (1)EDGCV patients demonstrated a positive R or r wave on lead Ⅰ(6/9) while a negative rS or qr wave was evidenced in other three groups (39/40). (2)A positive R pattern on lead V₁, V₅-V₆ (11/13) was presented in patients of DGCV2 group; R (without S or s) wave on V₁ (9/10), RS or Rs wave on V₅-V₆ were found in DGCV1 group; RS or rS wave was seen on lead V₁, R(without S)wave in lead V₅-V₆ (25/26) were found in EDGCV and PAIV group and the amplification of R wave in EDGCV was higher than V₁ of PAIV group.(3)Precordial lead transition zone was in front of V₁ for DGCV1 and DGCV2 groups (23/23), within V₁-V₃ for EDGCV group, but on V₂ or within V₂-V₃ for PAIV group.(4)Patients of DGCV1 and DGCV2 demonstrated a longer Pseudo delta wave time(PdW), intrinsicoid deflection time (IDT), significantly larger maximum deflection index (MDI) than those in PAIV and EDGCV groups (P<0.001). (5)The different characteristics of surface 12-lead ECG between VAs originating from DGCV and those from ventricular outflow tract and adjacent structure were as follows: ① The ECG features were similar between PVIA and LCC group, both demonstrated a rs wave on the lead Ⅰ, rS wave on V₁-V₂ and R wave on V₅-V₆; ②The ECG features were similar betweenEDGCV and RCC group, both presented with R or r wave on the lead Ⅰ, the QRS wave of precordial leads was similar as PAIV and LCC groups; ③A R wave on the lead V₁, V₅-V₆ was found in group DGCV2, and ILCC; ④Similar to the group Endo-MAA, patients in DGCV1 group also demonstrated a R wave on the lead V₁ and a Rs wave on V₅-V₆. Conclusion A positive R wave in inferior leads, a negative QS morphology in lead aVL and aVR are seen in all patients, but different electrocardiographic characteristics of PVC/VT originating from the different portions of the DGCV are presented on lead Ⅰ and V₁-V₆.