In this paper, we presented geometric CAD watermarking scheme for Architectural design drawings using line, arc, and circle components to prevent infringement of copyright from unlawfulness reproductions and distribution. The conventional CAD watermarking scheme can be applied to both line and arc components. But the proposed scheme consists of line, arc and circle watermarking schemes for three basic components of CAD design. After extracting line, arc and circle components from designed drawing, the watermark is embedded into the length of Line component, the angle of arc component, and the radius of circle component considering the robustness against various geometric transformations. The embedding strengths in each component are determined to be preserving the transparency of the watermark. By experimental result, we confirmed the robustness and the invisibility of embedded watermarks in several conversions of architectural design drawing.