Abstract: The quasi-Cathaysian structural system is one of the very marked and important types of structural system in the marginal-Pacific region of East Asia. After reviewing some scholars’ course of its research and existing prob- lems, the author divides the system into the archeoid, paleiod, mesoid, eoid and neoid structural systems in the light of the time of their generation, spatial distribution and characteristics of stress fields and calls them the structural system sequence in a general term. The evolution with time and directional structural shift were due to the effects of combined longitudinal compression and longitudinal shear, then longitudinal shear and finally com- bined longitudinal shear and latitudinal compression. The last one became stronger as the time elapsed. This is related to the periodic change and long- range deceleration of the earth’s rotational velocity. The classification and analysis of the systems of the Hexi-type structures in western China appear similar to this case. The revelation of these laws are of theoretical and prac- tical significance.