1 .Shool of Earth Science and Resources Management , Chang'an University , Xi'an 710054 , China ;
2 .North Road Engineering Construct Group of Hebei Province , Hebei Chengde 067400 , China ;
3 .Cheng jiao Mining of Yongcheng , Henan Yongcheng 476600 , Chi
Contour map is quite useful in practice .There is much arithmetic in automated generating contour map based on the Digital Elevation
models.In this paper , we focus on discussing a method on the base of DEM, including judging 、tracking and linking of the points of
same altitude .In order to confirm the contour' s uniqueness, the paper introduces a new method of tracking contour .While confirming the
direction of contour in the ”tracking-linking” procedure , the method not only is simply and utility , but also can avoid some uncertain result .
Practice show that the ”judging-tracking-linking” method describled in the paper is correct and practicable .