Legal analysis: the marriage law does not have for the definition of the third party, but generally refers to and has the legal marriage object, occurs outside the legal marriage of the third party couple, spouse. In the law third party does not violate anyone's rights, and not as a criminal definition.

Legal basis: "the Chinese people's *** and national code" Article 1,049 The man and woman who request to get married shall apply in person to the marriage registration authority for marriage registration. Where the provisions of this Law are met, the marriage shall be registered and a marriage certificate shall be issued. When the marriage is registered, the marriage relationship is established. If the marriage has not been registered, it shall be registered retroactively.