i am in nanjing i have to come kashghar through train what will be expense?

There is no direct train service between the two places and you have to transfer in Urumqi if traveling by train. I have to remind you that the whole rail journey takes much time. Nanjing to Urumqi: 40h and Urumqi to Kashi: 25h or longer. Anyway, the train fare for the firt route is CNY660 for a hard sleeper and CNY1,019 for a soft sleeper. For the second route, the fare is CNY182.5-343.5 for a hard sleeper and CNY319.5-527.5 for a soft sleeper.

If you are pressed for time, it is better to travel by air, in which way you still need to transfer in Urumqi.