Travel from XN to Chengdu, bus or train? Duration, price ?

Does XN means Xining City, the provincial capital of Qinghai Province?
If yes, there is no direct long-distance bus between these two places.
So you are suggested to take a train to your destination. There are two trains every day.
K1060 will take around 1d01h56min.T24 will take 22h43min. The ticket fare of Hard Sleeper is CNY 307.5.