It is important but difficult to generalize contour lines in cartographic generalization domain all along

and the graphic simplification of which is also a necessary difficulty. At present

existent simplification method of contour lines is mainly a geometrical approach

whose results after generalization process can hardly keep the primary shape characteristics. Based on analysis of area dividing and bend nesting of curve by the furthest visibility condition

a new generalization method of contour lines is proposed firstly. The experiment results show that the method is better than Douglas-Peucker algorithms on eliminating self-intersection

keeping character points

and can keep the shape after simplification better.