Abstract: In this paper, the Functional Graphic Object (FGO) technology under the background of self-developed FunGra drawing System is presented. The technology mainly includes the concepts of the FGO class model based on characteristic line model, the relationship mode of FGO realized by object calling and compound computing, the forced-transformation and directive-line method of FGO creation etc. The software development practice shows the validity and feasibility of FGO technology.