摘要：This paper discusses the semantic coherence in discourse translation from the perspective of thematic progression, and holds that in translating a discourse the translator should spare no effort to retain the original thematic progression pattern in the target text, but when the original thematic progression pattern cannot be directly retained, the translator should construct his own thematic structure and substitute progression pattern in the target text, thus to make it as readable as the original text without distorting the original information structure. This paper also attempts to explore the circumstances under which the original thematic progression pattern can be retained and the substitute should be reconstructed.