Aiming at bring into effect excruciation to defendant, bourgeois are incessant development and perfect, establish no additional punishment resulting from retrial procedure.

针对封建主对重审被告人刑，任意加重刑罚现象，资阶级在禁止不利益变更原础上不断发展和完善，在再审程序中确立了再审不加刑原。