According to the laws of China registration is not required for the copyrights to exist. However, in case there is a dispute about the copyrights the registration will speed up the case considerably and save costs.
Copyright registration can also be used as extra protection together with other methods to protect your intellectual property. For example, if your product includes a manual then the infringer will likely violate your rights by using your photos and texts which are simpler to prove than for example patent infringement. So, in a way, you can counter-attack the infringer on many fronts.