The Research on Represention and Realization of Map Symbol Based on Text

The paper put forward a descriptive rules of map symbol library on describing and organizing the point, line and area symbol with the way of plain text based on the visual variables and BNF, which can share map symbol resource cross platform and greatly enhance the work efficiency. Then realize the drawing and using of the example of the 1:50000 topographic map symbol with the rules, which gives some value of reference in craft brother.