Keywords: 
• seguence stratigraghy /
• Carboniferous /
• Anhui and Jiangsu provinces

Abstract: The Carboniferous system exposed from Anhui and Jiangsu provinces,has seven Iithogenetic units. Based on outcrop seguence stratigraphic anaIysis with particuIar attention to the key surfaces or poIyphase paIeokarsts deveIoped in the interruptions of sedimentation,nine types of Iithofacies, twenty types of microfacies and eIeven third-order seguences in the Carboniferous system are recognized. The Iower series of Carboniferous strata have six seguences,and the upper series have five. In the Iower series of Carboniferous strata,Yanguan stage are composed of seguence 1 to 2,and Datang stage from seguence 3 to 6.In the up-per series, Weining stage are composed of seguence 7 to 8, and Maping stage from seguence 9 to 11.According to the fea- tures of the bottom boundary surface,eIeven third - order seguences are cIassified into two sorts of seguence , which are type Ⅰseguence and type ". The bottom boundary surface of type ! seguence aII have cIear signs incIuding the differ-ent thickness eIuviums,the strong paIeokarst,the strata discontinutity,the immense changes of sedimentary patterns and traits,the huge and sudden aIternation of carbon and oxygen isotope vaIues and the disappearence and abrupt changes of organism evoIution. The third-order seguences of S2,S3,S5,S6,S7 and S11 beIong to I-type of sedimentary seguence,and S1,S4,S8,S9 and S10 Ⅱ -type. The third-order seguences are absent at times. The characteristics and genesis of each third-order seguences are described and discussed. The third-order se-guences in various paIeogeographic units and sedimentary environment can be correIated. Sea IeveI change rate and am-pIitude corresponding to these third-order seguences are discussed and highstand systems tracts iike Vaii' s marine seguence modei. Because of the difference of basin texture,fauit activity and materiai suppiy,the main controiied factors of seguence styie were different in steep siope,deep-water area and gen-tie siope. The major controiied factor of seguence styie on steep siope was fauit activity and materiai suppiy,and the nearshore subagueous fan was main sedimentary type；the factor controiied seguence styie in deep water area was reiative change of iake ievei,the sedimentary facies was characteristic of shaiiow-deep iake；the factor controiied seguence styie on gentie siope was reiative change of iake ievei and materiai suppiy,fan-deita or river-dominated deita was major sedi-mentary type. Therefore,the seguence modeis were estabiished separateiy on steep siope,deep-water area and gentie siope. A seguence was made up of iowstand,transgressive and highstand systems tracts with topographic break on gentie siope of Luxi depression. Lastiy,authors anaiyzed the condition of hydrocarbon accumuiation in different seguence frame-work,and pointed out that the iowstand and highstand systems tracts of seguence ! were rich in hydrocarbon resource,and were the main section for finding new hidden traps.