In this paper, a semi-automated mapping system, which can produ¬ce digital maps by using information acquired from pre-processing procedure, was introduced. To get a binary edge image, which is very important in vectori¬zation process, we applied adaptive smoothing and connection preserving thresho¬Iding algorithm. In mapper program, binary images are converted to vectors and for in-core data structure, extended PR quad tree was used. These procedures are dispatched to personal computers and workstations and through network resource sharing, the whole process was unified and simplified.