In order to carry out the principle of suspected crime out of nothing, we should prevent and control the mere illusionphenomena of the diseretion of suspected crime cases, such as investigation organ being unable to exercise the discretion oisuspected crime cases prosecution authorities being unwilling to make a decision on doubt not to prosecute , judicial organ notbeing bold in optionally making an acquittal lack of evidence. The maior causes of the phenomenon are no clear enough for the legislative orientation in investigation stage, unreasonable for the operation mechanism in the prosecution phase, imperfect forsafeguard mechanism in the trial phase. Therefore, we should endow investigation organ procedural discretion of suspectecrime case, fully realize the process funetions of Non-Prosecution for Doubt, increase the prepositional procedure for theacquittal of insufficient evidence, implement the functions of the discretion of dispute resolution.