Shader instructions and Compiler are designed for supporting 3D graphic shader 3.0 API. Variable-length instructions are proposed to reduce the size of hardware of graphic processor in SIMD structure by shortening the length of instructions. The designed shader compiler supports variable and two phased structured instructions, and can be programmable at ESSL level. Conformance Test proposed by Khronos group is accomplished to verify the design result of instructions and complier. The test result shows overall average 37% performance improvement at the 16 functions of basic GL shader.