In China, just like in most countries, registration is the quickest and cheapest means to get trademark protection: just 9 months and 100 $. Normally, you have no reason not to register if you really want to be protected.
However, if you are already using your trademark, but for whatever reason you have not registered it while someone else has already filed or even registered the same trademark, what can you do? If you do not have another prior right (copyright, design, personnel name...) that could invalidate the "obstacle" trademark, what is the solution? In that case, you still have several possibilities that are based on when and how you use your own trademark and also on the subjective status of the prior trademark owner.
Well-known trademark (13.2)
If your trademark is well-known in China after your extensive use or for other reasons (international traveling, TV or Internet spill- over effect, or just promotion), you can, according to article 6bis of the Paris Convention and article 13.2 of the China Trademark Law, oppose or invalidate this prior trademark and attack the registrant directly if he uses it.
Representative or agent (15.1)
If your trademark is not a well-known trademark (actually, this is difficult to prove), but the owner of the prior trademark was your representative or agent, you can, according to article 6quinqies of the Paris Convention and article 15.1 of the China Trademark Law, oppose or invalidate the registration and attack the registrant if he uses the trademark.
Minimum use and blatant bad faith (15.2)
But very often, the owner of the prior trademark is not your agent or distributor. In this case, article 15.2 of the new Trademark Law (2013), brings a possible solution. If (1) your trademark has been used (anywhere in China and no requirement of extensive use) and (2) if you can prove that, for reasons related to contractual or business contacts or to geographical circumstances, the owner of the prior trademark definitely knew the existence of your trademark, you have the ground for opposition or invalidation.
Certain influence and relative bad faith (32 in fine)
Finally, if you have none of the above, you still have article 32 of the Trademark Law to fall back on: “…nor shall an applicant pre-emptively register in an unfair manner a mark that is already in use by another party and enjoys a certain influence”. In this case, you do not need to prove any relationship with the prior trademark owner, but just need to prove that due to your own use, your trademark had obtained "a certain influence" when the prior trademark was filed.
There is a seesaw effect between the two factors: reputation and bad faith. When you have a relatively high influence, you will have to prove less of the applicant’s bad faith, and vice versa. There is no minimum influence as such. It all depends on how much evidence of the prior trademark applicant’s bad faith you can produce: the less evidence you have the more you need to elaborate on your own use.
Sometimes, none of the above works, or maybe you missed the statutes of limitation deadlines (3 months after preliminary publication for oppositions, or 5 years after registration for invalidation).
In that case you could be sued….
Certain influence and right to continuously use (59.3)
But, even if you are sued, you might still be able to get away and be allowed to continue using your trademark. Article 59.3 of the new Trademark Law can save you. If you had started using your trademark before (a) the application date of the prior registered trademark, and (b) the owner of the prior trademark started using his own mark, and if you can show that you had acquired a certain influence, then you are safe. The owner of the registered trademark cannot stop you from continuing using your trademark "within its original use scope". All he can do is ask you to add some other signs in order to facilitate the distinction…
This concept of "original use scope" is not defined in the law, and is rather vague…
In a case启航（Sail）(selected in the 2015 top ten influential cases of Beijing IP protection), the Beijing IP court enumerates a lot of factors to define the "original scope" (such as the same person, same or similar goods…) but does not mention any geographic limitation, the lack of which is good news for the prior user, but bad or even sad news for the later registrant who will be unable to stop a prior use from growing. The court should find a balance between the use and registration.