Abstract: Tarim Basin in Early Palaeozoic was not a uniform one, and after then it underwent multi-stage basin formation, multi-stage development, and multi-stage reconstruction. Finally it evolved into an overlay one. As a result, the Lower Palaeozoic of the Basin was characterized by multi-source hydrocarbon generation, multi-stage hydrocarbon generation, multi-stage migration and accumulation, multi-stage reservoir formation and multi-stage reconstruction. The factors controlling the oil-gas reservoir formation of Lower Palaeozoic could be summarized as òsource control, uplift control, slope control, surface control, fault control, and facies controló. Compared to the exploration idea of òselecting zone by determining bottomó of primary type basins of the Mesozoic and Cenozoic era in East China, the exploration idea of Tarim Basin should be òto select zone by determining sourceó. On the basis of confirming effective hydrocarbon kitchen, through the study and determination of fault, unconformable surface, transport layer, and the favorable exploration zone related to hydrocarbon kitchen, the exploration strategy of favorable zone might be determined as òdominated by exploration for oil, gas, or oil and gas simultaneouslyó, according to the thermal evolution degree of source rocks.

Key words: Tarim Basin, overlay basin, complex slope, Lower Palaeozoic, exploration idea, zone selection by determining source