According to the characters of abrupt change and gradual change,a twice difference based method and a window-difference maximum based method are proposed for abrupt change detection and gradual change detection separately.

Illustrated by some existing buildings,it is manifested that city architecture-the solidified music-shows the rhythm and cadence of continuity,gradual change,waving and overlapping,and therefore offers us the sense of artistic pleasure and enjoyment.

Although they lived in different ages and nations, Lenin and Deng Xiaoping held the identical idea about gradual change of economic system-the necessity of establishing economic system, how to start the gradual change and how to push the gradual change forward in a all-round way, etc.