Personal computer will be in fashion recently. The development of hardware makes progress at a tremendous pace. The promotion of CPU is from 486 to P-Ⅲ, and the hard disc's volume from 120MB to over 13GB. The software also has great growth. For example, the version of AutoCAD is from R10 to 2000. The update of software and hardware make the cost of digital mapping becoming familiar and cheaper so screen digitizing become one of the digital mapping methods. The paper is based on difference of using original draft and digital tools between screen digitizing model and others. And compare screen digitizing model with others about using material, equipment and working-hour.