Abstract: This paper proposes a new method for increasing roads based on unit influence domain to adapt to the request of the geographic information database updating.The method selects the right roads for the corresponding amount of the information according to a set of criteria in which the unit influence domain is the primary concern.Moreover,before generalization,this paper divides the whole region to several sub regions according to the road density contrast in the region using quad-tree segmentation method.Different density regions use different unit influence domain thresholds so that the updated road data has similar density distribution as the old one.Finally,the proposed method is the proven to be effective by an experiment