How did the yangtze river start?
Can it be detailed pleasee

We propose that the present Yangtze River system formed in response to regional extension throughout eastern China, synchronous with the start of strike–slip tectonism and surface uplift in eastern Tibet and fed by strengthened rains caused by the newly intensified summer monsoon.

some extra for ya  

Yangtze River starts from Jianggendiru Glacier, the southwest side of Geladandong Peak, the main peak of Tanggula Mountains, where is next to Kunlun Mountains, in the back-land of Qinghai-Tibet Plateau in western China. After this, it flows eastwards and pours itself into the East China Sea

i hope this helps