Pt、St就是指正常P、S波之后若干秒内出现的两种震相。其形状为波列,周期常为8—10秒,通常比P、S强。在震中距离6°—30°间为地震图上引人注目的震相。该震相在文献中虽然曾被片断地提到过,但是尚未见到过系统的研究,至今人们还不知道它们的性质是什么。本文是对该震相性质进行解释的初步尝试。考察的重点是它们的运动学特征。依据80多个地震的资料,其震中均分布在中国的台湾,日本的琉球、本州这个地震带上。 Pt, St refers to the normal P, S waves after a few seconds appear two phases. The shape of waves, the cycle is often 8-10 seconds, usually stronger than P, S. A striking phase of the seismogram between 6 ° and 30 ° from the epicenter. Although the seismological phase has been mentioned in the literature piece-by-piece, no systematic study has yet been found and so far it is not yet known what their nature is. This article is a preliminary attempt to explain the nature of this phase. The focus of the study is their kinematic characteristics. Based on the data of more than 80 earthquakes, the epicenters were all distributed on the seismic belt of China, Taiwan, Japan and Ryukyu and Honshu.