We investigate the expressiveness of existing XML keyword search semantics and propose Meaningful Connected Network (MCN) as a new semantics to capture meaningful relationships of the given keywords from XML documents. Our evaluation method adopts a two-step strategy to compute all MCNs. In the first step, we identify a set of query patterns from a new schema summary; in the second step, all query patterns are processed based on two efficient indices, partial path index and entity path index. The experimental results show that our method is both effective and efficient.