Company Act Article 120

A shareholder of limited liability may engage in the same business as that of the company either on his own account or on behalf of another and may also become a shareholder of unlimited liability in another company or a partner in partnership business.
中文原文 公司法第120條
有限責任股東,得為自己或他人,為與本公司同類營業之行為;亦得為他公司之無限責任股東,或合夥事業之合夥人。

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