In this paper, we present a new method for creating shadow texture atlas with which we can represent the self-shadow. Shadow texture atlas is a texture atlas with shadow information in each texel. Shadow texture is effective to represent high-quality shadow using the graphics hardware because it stores shadow information as color unlike shadow map which stores depth. However, it cannot represent the self-shadow and it takes a long time to create a shadow texture. To overcome these problems we present shadow texture atlas method. Shadow texture atlas can also represent self-shadow information. Moreover, we use shadow map to create shadow texture atlas instead of drawing all shadow casters. Our experimental result shows that our method performs at linear time and its speed is similar to the traditional shadow map method. Furthermore in comparison with shadow map method, our method can use mipmap filtering which is hard to achieve with shadow map method.