Abstract: In this paper, the topological properties of molecules are discussed by using subgraphs induced from molecular graph as the basic graph. The practical method is developed for evaluating a_K general formula of the conjugated molecules through deriving the graph of molecular graph. Applying this method, we have obtained the general formulas of a_K for common homologous conjugated molecules.

Key words: Graph theory, Subgraphs iduced by Molecular graph, Coefficients of eigenpolynomial equation, Conjugated molecule