A lawyer shall not reveal any of the client’s information relating to the representation without consent of the client. It is a lawyer’s ethical duty of confidentiality to prevent the lawyer from revealing the client’s information or misusing the information to the disadvantage of the client, even in face of the criminal investigation except the ongoing crime.
  The lawyer-client privilege prohibits a court or other government tribunal from compelling disclosure of confidential communications transmitted orally or in writing between a lawyer and a client concerning the representation 
  The confidentiality information does not include the identity of the client unless the client is a minor. Usually the client may waive the privilege, failure to claim the privilege when there is a chance to do so or intentional revelation of a significant part of the privilege information can be construed as consent of a waiver of the privilege. In addition, the lawyer may use clients information to the extent necessary against the claim between the lawyer and the client. 
  According to China law on lawyers, A lawyer shall keep confidential the things and information that he comes to know during his legal practice which his client except for the information where the client prepares to commit or is going to commit the crime which endangers the Country or any individual, but China law does not indicate that whether the lawyer shall reveal such information as an obligation or may reveal such information as an option. It is said that the lawyer may disclose such information at his/her discretion, and shall not be required to reveal such information. 
  The privilege information is not limited to client’s privacy and trade secret, it includes all the information that may affect the client in a negative way. The duty of confidentiality is the nature duty of lawyers which is recognizable by law, it is also a contractual obligation between the lawyer and the client even not expressly stipulated in the contract. Breaches of such obligation may entitle to client the rights to collect damages against the lawyer.