Abstract: In order to know the role of sea-air sensible heat transportation in cold flow snow-fall,in this paper,the sensible heat flux density formula is given,and vertical turbulenttranspo rtation process is described.Lastly the formula for total sea-air transportation heatin the condition of northwest cold flow over Bohai sea is provided.The calculation and analysis show that sea-air temperature difference and stability of cold air mass over the land are the im por tant factors for the amount of the transportation heat and cold flow snow fall.When the transportation heat from Bohai sea to air is more than 50 J·cm-2,or sea-air temperature difference is greater than 11.5℃,the cold flow snow fall is then possibly emerged in Jiaodong peninsula.