There should be a unity of thinking between history and science in research on the Zhang Heng's seismoscope. The major part in relevant historical literatures was written in a form of describable words for seismic phenomena. In spite of different conclusions made of the studies,the basic concepts and principles of seismology should be observed,which make up research basis and significance for correctly interpretion and analysis of historical documents. Because there are a number of discipline misunderstandings in seismology, clarification and correction are presented briefly based on seismological basic knowledge and history of science development. The discussed topics include:response direction of the instrument,distinction between seismoscope and alarm,quantitative range of parameters of the Longxi earthquake, seismological test and functions in seismology history. The paper also analyzes certain principal mistakes of some experiments which have been highly reported by media. It is worthwhile to point out that the purpose of reconstruction study is not confined on restoring a model;more valuable rewarding comes from searching on how ancients discover and used laws of nature,knowing well and analyzing their experience from the view point of modern science,so that we can have more inspiration and seismology knowledge.