Abstract: Famine was closely related to population migration in historical period. Tang dynasty, one of the dynasties with severe natural disasters, possessed such characteristics in natural disasters as multi-disaster, high frequency, and wide spread, and the crisis of people's livelihood was often caused. Because of the exploitation and squeezing of the feudal ruling class, the disasteraffected ability of peasants was very weak. Meanwhile, the government assistance was an utterly inadequate amount, and the corruption of the bureaucracy was severe. Therefore the victims of natural disasters often became impoverished and were forced to leave home. Especially after the mid Tang Dynasty, the war, political corruption and land annexation seriously weakened the capacity of disaster-resistance. Both famine and population migration were more and more serious in late Tang dynasty. In a word, famine greatly influenced the movement and migration of population in Tang dynasty.