Abstract: This paper proposes an approach for subgraph isomorphism testing from a set of priori given small graphs to a large graph issued on-line. In order to reduce the computational cost,based on DFS Code,an elaborate organization of a set of graphs is presented,and a look-ahead-pruning based algorithm of subgraph isomorphism testing from multiple small graphs to a large graph is proposed.Moreover, an index technique based on data miningis introduced.Analytical and experimental results show the on-line computational cost of the proposed method is much less than the state-of-the-art method and it is about one order of magnitude faster than the existing method with more than one order of magnitude less off-line construction time.