关键词: 不平衡性, 节点支持度, 相对支持度

Abstract: Traditional algorithms for frequent subgraphs mining have limits when dealing with biological datasets.Biological network has its own characters.Based on these characters，authors propose a new algorithm considering imbalance across datasets，called IFS（Iterated Function System），for mining frequent subgaraphs by relative support.Through dealing with the real protein interaction networks，it is proved that the algorithm is feasible.

Key words: imbalance, vertex support, relative support