The Arbitration Law of ROC Article 4

If either party fails to comply with the arbitration agreement and instead initiates litigation, the court shall, upon petition by the other party, issue a ruling to stay the legal proceedings and order the plaintiff to submit the dispute to arbitration within a specified period, except where the defendant has already conducted oral arguments on the merits of the case.If a plaintiff fails to submit the dispute to arbitration within the specified time period prescribed in the preceding paragraph, the court shall dismiss the lawsuit.For litigation provided in Paragraph 1, once the court has issued a ruling to stay the proceedings, the litigation shall be deemed withdrawn upon the rendering of the arbitral award.
中文原文 仲裁法第4條
仲裁協議,如一方不遵守,另行提起訴訟時,法院應依他方聲請裁定停止訴訟程序,並命原告於一定期間內提付仲裁。
但被告已為本案之言詞辯論者,不在此限。
原告逾前項期間未提付仲裁者,法院應以裁定駁回其訴。
第一項之訴訟,經法院裁定停止訴訟程序後,如仲裁成立,視為於仲裁庭作成判斷時撤回起訴。

English translation for reference only; the Chinese text prevails. Not legal advice.