Abstract: Since New China was established,the two sides of the straits have long been confronting each other both in military and politics due to dissidence between the Communist Party and Kuomintang.This paper analyses the main historical background and the difficult experience of the reopening-up of the closed doors between the two sides of the straits and points out the reopening-up has promoted the healthy development of the relationship between the two sides and laid the solid foundation for the vigorous development of China.