In this article, a algorithm CCN(Calculate Crossing Number) is put forward to study the crossing number. It is a very important development in graph planarity issue after planarity-determinant algorithm and embedding algorithm.

• 本文首次给出了较好的计算图的交叉数算法CCN(CalculateCrossing Number)，这是继图平面性判定算法，二连通图的平面嵌入算法之后在图的平面性问题上的一个最重要的进展。