Abstract: It is important whether the Suwan Movement exist or not for researching the geological history of the border region of Jiangsu ,Zhejiang and Anhui and recognizing the Changxing formation really. After making studies of the thickness change of Changxing formation,the features and genesis of the boundary clay band,the basal conglomerate and the contact relationship between strata,as well as the mutation of palaeobiota,we propose follows: first the Suwan Movement is existent,though it is not so extensive and strong that con be some-times called Suwan dislocation. Secondly the existence of Lishan-Jiangyin seawall is true. And it may be false to regard the upper part of Longtan formation distributed from Niutoushan,Anhui to Jiangyin,Jiangsu as the facies change of Changxing formation.