The vertical reinforcement spacing, which is not clear in present specifications, is an important parameter in the design of reinforced soil retaining wall and reinforced earth structure. According to the mechanism of reinforcement, shear band is concerned with the value of vertical reinforcement spacing, and also is closely related to the mechanical properties of reinforced soil. In this article, the causes and process of the formation of shear band are discussed, and then the research methods and results are summarized from three aspects including theoretical analysis, laboratory tests and numerical simulation. Results show that the thickness of shear band is affected by test apparatus and test conditions. Furthermore, some problems in current researches are pointed out. Finally, the development direction and prospect of shear band in the future are presented discrimination of the shear band, the stress-strain state within the soil of shear band, and the mechanics characteristics of composite reinforced soil mass will be the main directions of further research.