1 Introduction Internal kink mode driven by barely trapped suprakthermal electrons is reported on D Ⅲ-D tokama . This instability is most active when electron cyclotron current drive （ ECCD ） is applied on the high field side of the flux surface. It has a bursting behavior with poloidal/toroidal mode number m/n = 1/1. In positive magnetic shear plasma this mode becomes fishbone instability.
WANG ZhongtianLONG YongxingDONG JiaqiWANG LongZonca F.
