legal ground
Article 233 of the Criminal Procedure Law of People's Republic of China (PRC)
The people's court of second instance shall conduct a comprehensive review of the facts ascertained in the judgment of first instance and the applicable laws, and shall not be limited by the scope of appeal or protest. * * * If only some defendants appeal in the same criminal case, the whole case shall be examined and handled together.
Article 234
The people's court of second instance shall form a collegial panel to hear the following cases:
(a) the defendant, the private prosecutor and his legal representative raised objections to the facts and evidence ascertained in the first instance, which may affect the conviction and sentencing;
(2) An appeal case in which the defendant was sentenced to death;
(3) Cases protested by people's procuratorates;
(4) Other cases that should be heard in court.
If the people's court of second instance decides not to hold a hearing, it shall interrogate the defendant and listen to the opinions of other parties, defenders and agents ad litem.
The people's court of second instance may hear an appeal or protest case in the place where the case occurred or in the people's court that originally tried the case.