Political Parties Act Article 11

Citizens of the Republic of China have the right to join or quit political parties.Political parties shall not recruit as members citizens of the Republic of China who are under sixteen (16) years of age. Political parties shall not force citizens of the Republic of China to join or quit the said party; this provision shall not apply to party members who have been expelled from the party for disciplinary reasons.Political party members are defined as those listed in the party roster.
中文原文 政黨法第11條
國民有加入或退出政黨之自由。
政黨不得招收未滿十六歲之國民為黨員;非基於國民之自由意願,不得強制其加入或退出政黨。
但對黨員為除名之處分者,不在此限。
黨員身分之認定,以登載於黨員名冊者為準。

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