Numerous studies have revealed that there has been considerable progress but still debate concerning the NS-trending structures in this vast area. Some aspects are suggested as follows: 1) the NS-trending structures consist of not only the extensional structures, but also the compressional structures such as folds, overthrust faults and superimposed structures; 2）the terminology rift systems can’t be applied to represent all of the extensional structures, and the rift systems and graben systems also can’t represent all of the NS-trending structural features; 3）the NS-trending structures in the study area were initiated during the Eocene to the Oligocene; 4）the NS-trending extensional structures were initiated in the northern Tibat to southern Qinghai zone rather than in the Himalayas; and 5）a phase of temporary EW-trending compressional stress field once occurred on the Plateau during the latest Oligocene to the earliest Miocene, and resulted in the formation of various compressional structures.