After registering a trademark, you need to register the copyright because: 1 Copyright registration is beneficial to prove the ownership of works and can play a very good auxiliary protection role. 2. The trademark application cycle is long and the copyright registration cycle is short. Before the trademark is approved for registration, the copyright certificate, as a prior right, can play a certain role in trademark defense. 3. According to the relevant provisions of the Trademark Law and the Patent Law, if an artistic work is applied for registration of a trademark by others, or if a graphic trademark is registered by others in other categories, it may use the prior right of copyright to raise an objection or declare it invalid. 4. Trademark registration certificate can only determine the ownership of trademark rights, and cannot be used as the basis for determining the ownership of copyright.