Li and Du both were the preeminent poets in Tang Dynasty. Li became Duís friend immediately when they met. Nevertheless, they had to separate soon,because Du had to go to another city to visit his relatives. Du usually wrote some poems to express his wishes to meet Li. And these poems are very popular now and become a symbol of their friendship. So long distance wonít make two good friends separate. On the contrary, due to long distance, friendship can become more stable.