Abstract: Shadow generation is essential to the realistic display of computer graphics,and the algorithm of shadow maps is the mainstream for shadow generation.In this paper,the algorithms of shadow maps are systematically studied,focusing mainly on the development in recent years.The paper summarizes the fundamental ideas,characteristics and application environments for various types of shadow map algorithms from three aspects,the number,parameterization and contents of the shadow maps.After considering the three aspects,appropriate shadow map algorithms can be taken based on the scene,in terms of the light type,memory consumption,real-time requirements,hardware support and special shadow requirements.Finally,based on the development of technology and application requirements,some directions to the future investigation in this area are given.