BD-GKS3D is a 3D graphical support software developed according to the international standard GKS-3D (ISO 8805). This paper discusses the principles of designing this software: conforming to the international standard, and as fast as possible efficiency; the implementing strategies, which include the compatability of GKS and GKS-3D, clipping and transformation, implementing environment, data structure of the segment and 3D input, etc. Finally, the amount of work of developing BD-GKS3D, the relations between CKS-3D and PHIGS,CGI are discussed.