Virtual environment ia an advanced human—computer interface which use multiple media to generate human'S visual and auditory effects．A concept of overall repre-senting temporal and spatial information of sound was provided in this paper．Infinite loudspeakers were addressed in 3D space to represent temporal reality and spatial reality of a sound from any spatial direction．With discussing the essence of spatial sound，a realistic spatial sound rendering algorithm based on 3D vector analysis and a system implements-tion based on time—critical computation were provided．Comparing with traditional three —dimension sound synthesis method based on HRTF,this method required less computa-tion to generate more realistic sounds，