There were at least four microcontinents on the eastern margin of the Tarim paleocontinent prior to Early Paleozoic. They are, from north to south, Longshoushan, Qilian, Oulongbuluke and Qaidam, which have somewhat similar yet different Early Precambrian metamorphosed basements and Mesoproterozoic meta_sediments. Quite complex geological evolution was detected along the margins of these microcontinents, especially along the margin of Qaidam, where a Neoproterozoic granite gneiss belt over 700 km long is developed. In addition, Cambrian and Ordovician volcanic arc and ophiolite melange were superimposed upon the microcontinental margins. From north to south, the north Qilian ophiolite melange,the south Qilian ophiolite melange, the Shaliuhe_Yuqiahe high_pressure and super high_pressure meta_morphic belt and the Qingshuiquan ophiolite melange in central Kunlun Mountains are developed between two adjacent microcontinents, representing suture belts between two microcontinents. The suture belts are from Cambrian to Ordovician in age. Geological characteristics of these microcontinents, especially the characteristics since Neoproterozoic, are generally similar to features of the Tarim paleocontinent. However, the time and location of amalgamation between the Tarim and the microcontinents require further investigation.