Abstract: In this paper some heat flow values the geothermal in the Bohai sea and adjacent region are described.The temperature distribution, geothermal gradient and heat flow in this region have a tendency of increasing gradually from the land to the sea. This tendency is well correlated to the geotectonic features and the structure of the crust and upper mantle, and approximately coincident to the features of other geophysical field in this region. It is suggested that the possible upwelling of the material from the upper mantle in this region, especially in some segments of Tangchen-Lujiang fault belt, caused the deep parts of the crust different in temperature and density, leading to high concentration of thermal stress.