The proposed ultrasound volume rendering system concists of 3D digital scan conversion (DSC) part and volume rendering (VR) part, which requires large memory space to store 3D data and high computation power to process them. Though there are several methods to reduce the computation amount such as early ray termination in VR, it is very difficult to process 3D DSC in real time. The 3D DSC converts the 3D sampled data in spherical coordinates or cylindrical coordinates into the 3D data in Cartesian coordinates. Since the input data of ultrasound volume rendering system are obtained from 3D $R- heta$ sampling, 3D $R- heta$ interpolation has to be performed as the 3D DSC algorithm. The 3D $R- heta$ interpolation requires large computation amount. We can reduce the computation amount by applying the fast processing methods of volume rendering and the characteristics of TMS320C6201. Only the part of the data needed to be rendered is converted by the early ray termination and voxel skipping method. And we can move the data between memories efficiently by using the DMA and using the 16-bit data type. This paper proposes a fast technique of 3D DSC algorithm for 3D ultrasound images, which is appropriate for volume rendering