Abstract: Machine translation, which aims at automatically translating between natural languages using computers, is one of important research directions in artificial intelligence and natural language processing. Recent years have witnessed the rapid development of neural machine translation, which has replaced conventional statistical machine translation to become the new mainstream technique in both academia and industry. This paper first introduces the basic ideas and state-of-the-art approaches in neural machine translation and then reviews recent important research findings. The paper concludes with a discussion about possible future directions.