Legal analysis: the power of attorney needs the signature of the client. If the power of attorney is in written form, the power of attorney shall specify the agent's name, agency matters, authority and time limit, and shall be signed or sealed by the principal. So the power of attorney needs the signature of the client.

Legal basis: Article 163 of the Civil Code of People's Republic of China (PRC) Agency includes entrusted agency and legal agency.

An entrusted agent shall exercise the power of agency as entrusted by the principal. A legal agent shall exercise his power of agency in accordance with the provisions of the law.