Abstract: Middle Cambrian strata in Taizihe area of Eastern Liaoning Province, including Jianchang Formation and Mantou Formation, belongs to epicontinental deposit. According to the features such as lithological combination, sedimentary cycle and lithofacies, the Middle Cambrian stratum is divided into 3 third-order sequences, including 1 type-Ⅰ and 2 type-Ⅱ sequences, and 30 parasequences are identified. The condensed member is not developed and the sequences are all composed of transgressive system tract and high system tract.