Abstract: Under the leniency system of guilty plea and punishment， the main reasons resulting in defense conflicts are “the prosecutorial-led model”， “the prosecutorial-trial cooperation model”， and the professional ethics of defense lawyers with the consideration of the defendant's own interests， and the differentiated right of legal assistance between defense lawyers and duty lawyers. In the case of guilty plea and punishment， defense lawyers should deal with defense conflicts based on their loyalty obligations， adhere to the principle of limited independent defense， strengthen their negotiation obligations， and perform their real obligations to the court under specific circumstances. The defense conflicts in the case of guilty plea and punishment in the review and prosecution stage should be handled separately by distinguishing between the defense conflicts of “guilty plea” negotiation and “punishment” negotiation， and the procedural mechanism of pending prosecution and defense disputes in the review and prosecution stage should be established. The defense conflicts in the case of guilty plea and punishment at the trial stage should be handled separately by distinguishing between “qualitative” and “quantitative” controversial cases， and the procedural rules for the defense to deny guilty plea and punishment at the trial stage should be constructed.

Key words: guilty plea and punishment; consensual prosecution and defense; defense conflict; negotiation obligation