Civil Associations Act Article 37

The members of a vocational association shall be those who are engaged in the corresponding occupation within the organizational area of the association.Vocational associations shall not refuse membership to those who are eligible for membership.
中文原文 人民團體法第37條
職業團體以其組織區域內從事各該行職業者為會員。
職業團體不得拒絕具有會員資格者入會。

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