如果要将使用作为保持注册的前提，则只有至少3年连续不使用，商标所有人又未出示妨碍使用的有效理由，方可撤销其注册。

• If use is required to maintain a registration,the registration may be cancelled only after an uninterrupted period of at least three years of non-use,unless valid reasons based on the existence of obstacles to such use are shown by the trademark owner.