Code of Civil Procedure Article 255
After the service of the complaint, the plaintiff may not amend his/her claim or raise additional claims, except in case of any of the following circumstances:1. Where the defendant agrees;2. Where the amendment or addition of the claim is based on the same transaction or occurrence;3. Where only the demand for judgment for the relief sought is expanded or reduced;4. Where the change of circumstances makes it necessary to replace the original claim with another claim;5. Where the claim shall be adjudicated jointly with regard to several persons and one or several such persons who are not parties are joined as parties;6. Where the existence or nonexistence of a certain legal relation, based upon which relation the case shall be decided, becomes disputed in the course of the proceeding and an additional claim for a declaratory judgment confirming such legal relation against the defendant is raised;7. Where it would neither severely obstruct the defendant's defense nor delay litigation. Where the defendant proceeds orally on the merits without objecting to the amendment or addition of claims, he/she shall be deemed to have agreed to such amendment or addition.
中文原文 民事訴訟法第255條
訴狀送達後，原告不得將原訴變更或追加他訴。
但有下列各款情形之一者，不在此限：
一、被告同意者。
二、請求之基礎事實同一者。
三、擴張或減縮應受判決事項之聲明者。
四、因情事變更而以他項聲明代最初之聲明者。
五、該訴訟標的對於數人必須合一確定時，追加其原非當事人之人為當事人者。
六、訴訟進行中，於某法律關係之成立與否有爭執，而其裁判應以該法律關係為據，並求對於被告確定其法律關係之判決者。
七、不甚礙被告之防禦及訴訟之終結者。
被告於訴之變更或追加無異議，而為本案之言詞辯論者，視為同意變更或追加。
但有下列各款情形之一者，不在此限：
一、被告同意者。
二、請求之基礎事實同一者。
三、擴張或減縮應受判決事項之聲明者。
四、因情事變更而以他項聲明代最初之聲明者。
五、該訴訟標的對於數人必須合一確定時，追加其原非當事人之人為當事人者。
六、訴訟進行中，於某法律關係之成立與否有爭執，而其裁判應以該法律關係為據，並求對於被告確定其法律關係之判決者。
七、不甚礙被告之防禦及訴訟之終結者。
被告於訴之變更或追加無異議，而為本案之言詞辯論者，視為同意變更或追加。