At first, the paper introduces the concept of blockchain and analyses the characteristics of credible, decentralization, traceability, cooperation, high reliability that blockchain has. The paper then defines technology patterns to apply blockchain to electronic records management according to data scope that embraces three kinds: to put hash digest on blockchain, to put hash digest and part of metadata on block chain and to put content and all of metadata on block chain. The technology frame and principle of every pattern is discussed. Three technology patterns are compared from cost, authenticity, long-term nature, confidentiality and applicability.