You should register your trademark if you do any interstate commerce of any kind. That is the requirement for the USPTO to approve and issue a trademark to a company. The American market is still the worlds biggest, but China is growing rapidly and is about to replace Japan and the worlds largest market.
Things are different in China as compared to the United States. In America, your trademark is for your business and if there is one similar in another region that is in another type of business, it could still be approved. In China it is first come, first serve. Preferential treatment of Chinese companies will occur but by registering first in this vast market is the best chance you can keep your business.
This registration should occur for any company doing business there. The most important are the ones involved in manufacturing. It has happened before and will occur again, when a Chinese entrepreneur finds an unprotected product being produced in their country. By submitting a registration for a trademark to cover that product, even one they are not producing, it will be granted to them. You will not be able to export you products until you pay the fee that the trademark owner requires. This is not fair but is considered a wise business move for many Chinese.
The cost of this filing will be minimal of $535 US that includes the research on Chinese trademarks and the registration fees. This will only cover one mark in one class. One thing American will not be able to do on their own is to register your trademark form themselves unless they know the Chinese language. That comes at an additional charge.