Abstract: Long short-term memory (LSTM) is mostly used in fields of speech recognition, machine translation, etc., owing to its expertise in processing and predicting events with long intervals and long delays in time series. However, most of existing neural network acceleration chips cannot perform LSTM computation efficiently, as limited by the low memory bandwidth. ReRAM-based crossbars, on the other hand, can process matrix-vector multiplication efficiently due to its characteristic of processing in memory (PIM). However, a software tool of broad architectural exploration and end-to-end evaluation for ReRAM-based LSTM acceleration is still missing. This paper proposes a simulator for ReRAM-based LSTM neural network acceleration and a corresponding training algorithm. Main features (including imperfections) of ReRAM devices and circuits are reflected by the highly configurable tools, and the core computation of simulation can be accelerated by general-purpose graphics processing unit (GPGPU). Moreover, the core component of simulator has been verified by the corresponding circuit simulation of a real chip design. Within this framework, architectural exploration and comprehensive end-to-end evaluation can be achieved.