Hi Leo
Greeting from Peggy, Top China Travel.
I've got that you are looking for a tour to Zhangjiajie, Shanghai and Xian from Hong Kong.
According to the flight information I've got this moment, there is no direct flight from Hong Kong to Zhangjiajie. Now, a suggested way to these three cities can be Hong Kong - Shanghai - Zhangjiajie - Xian - Hong Kong.
The reason is that the flights from Shanghai to Zhangjiajie are easily to book because there are more flights to choose.
And from Zhangjiajie to Xian there are two night flights which can cut down 1 night in Zhangjijie for saving the money.
And a tour covered these three cities may be a 10 days. And if you would like to have a tailor-made tour like this, I can do it for you once I have got the following:
1) When do you want to have this tour
2) How many days do you plan to travel
3) How many people will travel together?
4) Which hotel star do you prefer to chooe? 3, 4, or 5 star
Thanks for your time
Peggy