Chinese CHI 2015 is associated with CHI 2015 as one of the Asian CHI Symposia (ACHIS, You may register Chinese CHI through the CHI 2015 Attendee Registration website:

To register Chinese CHI, you must also register for at least one day of the CHI conference. Fees for Chinese CHI are Attendee $250 and Author $235. One-day registration for CHI is $300 for ACM or SIGCHI members or $375 for non-members if registered by *March 6, 2015* (early registration deadline). 
Please also make sure that you choose the right Asian symposium in the registration site. We're Symposia 01, and the fee is higher than other Asian symposia.
If you're an author of an accepted paper, poster or special track paper, please email the program chairs at to obtain the special registration code if you haven't had the code."