By using the SLC(Single-Link Cluster)method,this study worked in three respects:(a)set up three-dimensional(3-D)SLC software that can deal with a large catalogue of earthquakes and analyze the characteristics of earthquakes’ clustering and scattering in time-space:(b)defined several parameters to describe the distinguishing feature for the SLC frame and developed a technique to calculate the 3-D SLC frames and these parameters with gradual time-sliding,and inspected their variations with time,especially before large events; and(c)by using these means,treated the earthquake catalogue in the top area of the Kunlun-Altun-Arc as well as some valuable results that had been obtained. By using the SLC (Single-Link Cluster) method, this study worked in three respects: (a) set up three-dimensional (3-D) SLC software that can deal with a large catalog of earthquakes and analyze the characteristics of earthquakes’ clustering and scattering in time-space: (b) defined several parameters to describe the distinguishing feature for the SLC frame and developed a technique to calculate the 3-D SLC frames and these parameters with gradual time-sliding, and inspected their variations with time , especially before large events; and (c) by using these means, treated the earthquake catalog in the top area of ​​the Kunlun-Altun-Arc as well as some valuable results that had been obtained.