From your given information, I can see there shouldn't be any problem with the connection as your iphone prompt to checking with your itune ("正在尋找...."). It's likely that your software firewall/anti virus program blocked the data.
Solution:
(1) check if "Bonjour" has been installed (normally installation comes with itune); and (2) Try to disable the firewall/antivirus and verify again.
If that's the case, please drag "bonjour" and "itune" into the 'trusted list' of your firewall program.
Bonjour, also known as zero-configuration networking, enables automatic discovery of computers, devices, and services on IP networks using industry standard IP protocols. It is a key component of Apple applications (e.g., iTunes, iPhoto), services (e.g., MobileMe) and devices (e.g., Apple TV, and Airport). Developers can easily leverage Bonjour from both Mac OS X and iOS.