Associated trademarks refer to several similar trademarks registered by trademark owners on the same commodity, or several identical or similar trademarks registered on different commodities of the same category. These mutually similar trademarks are called joint trademarks. Among these trademarks, the main trademark is the first registered or mainly used, and the rest are joint trademarks. Because of the particularity of the function and function of joint trademarks, one of the trademarks is idle and will not be revoked by the State Trademark Office. As the overall function of the joint trademark is similar, the joint trademark shall not be used or transferred across categories.

A joint trademark generally refers to several similar trademarks registered by the same trademark owner on the same or similar goods. Among these trademarks, the main trademark is the first registered or mainly used, and the rest are joint trademarks. The purpose of registering a trademark is to obtain the exclusive right to use a trademark, protect the use of a trademark on goods or services through law, and strive to create its own trademark brand. In order to achieve this goal and ensure their own interests, enterprises often formulate some trademark strategies suitable for their own actual characteristics. For example, on the basis of existing registered trademarks, registering protective defensive trade mark is one of the common means. These strategic registered trademarks usually include "Joint Trademark" and "defensive trade mark".