It is nowadays clear that Hebrew tradition must have received its material for biblical account of the Flood from some Mesopotamian sources. The XI Tablet of the Gilgamesh Epic is acknowledged by most scholars to be the prototype of biblical account, but also other opinions were presented. The paper deals with interrelationship between the biblical account and Mesopotamian document (tablet) from Nippur The Flood Story. There is shown detailed correspondence – as well as difference – of the two to proof the hypothesis that the author of Yahwistic (J) version in Genesis has adjusted the data of the document to his own needs and concepts.