A programmable graphics pipeline including the shader in the embedded systems increases flexibility and enables customizations of vertex and fragment processing, and it also provides the programmer with various special effects essential in development of realistic 3D mobile games whereas the traditional fixed-function pipeline does not. In this paper, we design a unified shader integrating vertex shader and fragment shader, define a memory structure for the unified shader, and present an operating process to construct the memory structure and execute compiled shader program by passing it to the unified shader using the OpenGL ES 2.0 APIs. We are satisfied with the result from implementing the unified shader and its OpenGL ES 2.0 APIs. It can be used as a development platform for 3D mobile games.