As a pilot system put forward by the 4th Plenary Session of the 18th CPC Central Committee, the system of lenient punishment for admission of guilt and acceptance of punishment is facing quite a few theoretical problems regarding evidence application in practice. The maintenance of the current standard of criminal proof is more favorable for guaranteeing the substantive justice. While the burden of proof is being assigned, the admission of guilt and the acceptance of punishment shall be differentiated, which means no change in the proof for conviction while the criterion of "he who asserts mustprove" is applicable to the part of sentencing. The defendant's voluntariness and authenticity shall be reviewed, and the conviction shah be differentiated from sentencing in terms of the specific criterion for evidence review. The rules of evidence may be in principle lenient and simplified moderately, while contradictory problems between the principle of directness and verbalism, rules of defective evidence correction, the voluntary confession rule and lenient punishment for admission of guilt and acceptance of punishment, need further exploration.