Based on the identification of sequence boundary through outcrops,seismic data,well logs and analytical data,the Nadu Formation and Baigang Formation of the Eocene of Paleogene in the Baise Basin can be divided into one secondorder sequence,and further into three third order sequences The Member 3 of the Nadu Formation forms Sequence Ⅰ,the Member 2 and Member 1 of the NaduFormation form Sequence Ⅱ,and the Baigang Formation forms Sequence Ⅲ Sequences Ⅰand Ⅱ were deposited during the faulting period of the basin,during the period alluvial fan facies,fluvial facies,delta facies,fan delta facies,shore shallow lake subfacies,and deep lake subfacies were developed  Sequence Ⅱis characterized by a wide range of lake sedimentation with a great thickness,and the thick  bedded mudstones of deep lake subfacies are the main source rocks and regional cap rocks in the basin Sequence Ⅲ was deposited during the depression period of the basin,during the period alluvial fan facies,fan delta facies,fluvialfacies,delta facies,and shore  shallow lake subfacies were developed  The Paleogene in the Baise Basin experienced a process from the deposition of fluvial facies or alluvial fan facies to fluvial and delta facies,and then to lake facies (fan delta facies),and finally to fluvial facies  This indicates that the  Baise Basin experienced a complete cycle of evolution from the early rifting stage to expansion,and then to shrinkage  In the lowstand system tracts of sequences Ⅰ andⅡ,sandstones of fluvial and delta facies are well developed in the central faulted sag,the southern subsag of the Tiandong Sagand the northern faulted nose of the Nabi Uplift along  the long axis  These sandstones are in mature source rock areas with a favorable condition for reservoir formation,and are in the potential areas for the exploration ofchannel lithologic pools  In the transgressive and highstand system tracts of sequence Ⅱ,fan delta facies were developed along the northern steep slope and their sandstones are interfingered with source rocks which are favorable for the formation of hydrocarbon pools,and are easy to form a great deal of updip pinching lithologic reservoirs