Based on cluster analysis,the time interval characteristics of strong earthquakes (M≥7.5) along the circum-Pacific region since 1890 are analyzed and it is found that the cluster characteristics of earthquake time interval are similar when starting magnitude is less than 8.0.When the starting magnitudes are larger than 8.0,the cluster numbers are more detailed.In a preliminary seismic active period,it can be divided into relative high active one (the earthquake time interval is about 1 year) and relative low active one (the earthquake time interval is about 6 year).Finally,taking the last active period as an example,a counter-clockwise rotation is shown for the migration of M≥8.0 earthquakes.