Abstract: This paper presents an approach of using texture mapping and GPU based method for realizing focal region based volume rendering.The proposed method first labels the volumetric data into three parts based on the mechanism of stencil buffer test.Then the data model is rendered using texture mapping method.The approach also adopts GPU-based method to render the context region with volume silhouettes, and also realize the multiple transfer function specification process based on pixel transfer function.The proposed method shows its good performance in the implementation and function extension.