Abstract：According to both the principle of sequence stratigraphy and the comprehensive analysis of drilling,crop data plus seismic data in Tarim Basin,we can divide the Palaeozoic group into 9 sequences or 27 depositional system tracts In terms of sequence and depositional system tract,lowstand and highstand system tracts in a sequence have various sand bodies,which are the favourable places for hydrocarbon accumulation The transgressive system tract includes source rocks and became a good barrier bed As a result,a whole sequence consists of source rock,reservoir and barrier bed to form a nonstructural trap Having analysed the combinative relation between sequence and system tract in Tarim Basin,we can predict the following Palaeozoic geologic bodies where nonstructural traps can be discovered likely: •Continental shelf slope consisting of Cambrian system and low Ordovician series. •Top eroded zone of mid-a?pper Ordovician series. •Top eroded zone of Permian system in the southwest depression. •Lowstand bottom fan in mid Ordovician series. •Lowstand bottom fan in upper Ordovician series. •Lowstand bottom fan in Silurian system. •Tazhong delta in mid Ordovician series. •Southern Yingmaili delta in mid Ordovician series. •Tazhong delta in Carboniferous system. •Tabei delta in Carboniferous system.
