Yes, the authenticity of the signature can be determined according to the fax address and the comparison with the signature of the previous party; Fax contract has legal effect. The written form prescribed by law refers to the forms in which contracts, letters and data messages (including telegrams, telexes, faxes, electronic data interchange and e-mails) can tangibly express the contents contained. Article 10 of the People's Republic of China (PRC) Contract Law: The parties may conclude a contract in written form, orally or in other forms. If laws and administrative regulations stipulate that it should be in writing, it should be in writing. If the parties agree to use written form, it shall be in written form.