How could I reply an email from a potential professor?
The university uses a system in which admissions isn't under the control of individual professors, as is true in the US, for example. You need to apply and be accepted before he can really do anything for you.
Your reply should be to thank him, and say that you are applying. You needn't say any more at this time, as he gets a lot of such mail and likely won't continue the conversation until you are accepted.
This reply is actually more than you will receive from many (most?) professors whose university uses such a system.
Other places in which professors actually hire PhD students directly it would be very different.
You would also be wise to spend some time, once you arrive at a new institution, to consider your options for advisors. Often you don't need to choose one immediately and can explore the reputations of various professors with other students. An in-person interview with a prof is the best way to establish the relationship initially.
From my experience, this means that he would be happy to speak to you after you've been accepted to the program. It's a polite way of saying, "Come back to me after you've been offered—and have accepted the offer to—our program." I wouldn't read much beyond that, including not assuming that he has open positions in his lab group.
Zhubenwuxin about 19 hours
I'm applying to a PhD program. I contacted one professor and told him that I would like to join in his research team. He replied to me as below. Was this a positive response? How could I reply to this email?
"Good luck with the PhD applications! Happy to talk with you if you come to XXX (university name)."
L_W over 3 yearsIt sounds like the professor understood you want to apply to the PhD programme of that university and wishes you good luck for the application. Are you sure the PhD program allows you to apply to professors directly or does the program have a centralised application system? Are you certain that your E-mail specifically asked about joining his group as a PhD?