An experimental study on rotating detonation engine with the slot-orifice impinging injection method was presented in this paper. Reactants were gaseous H-2 Air mixtures and ignited by an automotive spark plug. The engine was initiated successfully and rotating detonation wave propagated continuously and steadily in the circumferential direction. Through the detailed analysis on the initiation and propagation process of rotating detonation wave, it was found that deflagration-to-detonation transition (DDT) was observed in the annular combustion chamber, and the DDT time exhibited an obvious randomness. For the operating conditions which the rotating detonation wave propagated stably, the fluctuation of the pressure spike of detonation wave was relatively small, and the detonation wave propagated continuously without interruption; for the operating conditions which the detonation wave was unstable, the fluctuation of pressure spike of detonation wave was relatively large, and the interruption occurred, which might result in the change of propagation direction of rotating detonation wave. And in some operating conditions, a new phenomenon that strong detonation and weak detonation occurred alternately was found. Besides, in order to obtain the success rate of rotating detonation wave initiation with automotive spark plug, repeatability experiments were carried out. The results show that the success rate was up to 94%. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.