The rapid development of information technology gives rise to the big data era. Big data has become an important wealth of information society, and has provided unprecedented rich information for people to further perceive, understand and control the physical world. However, withthe growth in data scale, dirty datacomes along. Dirty data leads to the low qualityand usability of big data, and seriously harms the information society. In recent years, the data usability problems have drawn the attentions of both the academia and industry. In-Depth studies have been conducted, and a series of research results have been obtained. This paper introduces the concept of data usability, discusses the challenges and research issues, reviews the research results and explories future research directions in this area.