Abstract: ook-thickness is regarded as a topological standard to classify graphs.In general，it is a NP-complete problem to calculate the book-thickness of a graph or embed it into a book.In this paper，a book-embedding scheme is constructively obtained for the RNA secondary structures in Rivas-Eddy class by using the secondary-structure graphic grammar and the vertex coloring of the cross-relation graph，and the book-embedding classification can be performed furthermore.This method has a polynomial time complexity，which can provide useful reference to solving the NP-complete problems.

Key words: pseudoknots, RNA secondary structures, book embedding, vertex coloring, clique number, chromatic number, perfect graphs

摘要： 书嵌入数是对图进行分类的一个拓扑标准，通常来说，计算一个图的书嵌入数及给出一种嵌入实例都是NP完全问题。针对Rivas-Eddy（R&E）类中RNA分子的二级结构图，从二级结构图的语法出发，通过其交叉关系图的点着色，构造性地得到了RNA分子二级结构图书嵌入的具体实现方法，完成了对RNA分子二级结构的书嵌入分类。该方法具有多项式时间复杂性，为求解NP完全问题提供了有益的参考。

关键词: 假结, RNA二级结构, 书嵌入, 点着色, 团数, 色数, 完美图, ,