On the basis of the shifts of continental margin since Mesozoic time and the patterns of stress action during tectonic movements in the areas of the east China and the eastern Asia as a whole

it is suggested that the Neoca-thaysian Systems were generated after Whaiyang movement which took placeat the ead of middle Triassic

and now these Systems occupy a broad terri-tory.east of the north-south tectonic structures

extending from Mt.Helan through Mt.Longmen to central Yunnan.Properties in stages of generation and development of Neocathaysian Sys-tems

principles of their division and controls of oil and gas are the primarypoints required to be discussed in this study.According to data on sedimentation

structures and tectonic movements

the process of development of the Neocathaysian Systems can be divided into three stages

namely:①La-te Trissic-Jurassic

②Cretaceous-Paleogene

and ③Neogene-Quarternary.For the purpose of petroleum geology

it is considered to be necessaryto distinguish the primary sedimentary basins from the later ones in orderto have a good knowledge of the process of generation of different subsidence regions and it is emphasized that of prime importance are controls occur redunder a variety of conditions

such as ordinal or seguencial controls by various degree of tectonic structures

composite controls by the same tectionic stru-ctures aud composite controls by different tectonic structures.Finally

thebasic features of oil and gas controls by stages of Neocathaysian Systems arealso discussed thereafter.