Convincing evidence should support a series of fact finding developed by a judge's inner conviction in order to achieve a particular result. This can reflect conclusive proof through maintaining high standards of evidence quality that is acceptable for a particular situation. This article writes about four facts, including behavioral entity facts, behavioral formed facts, behavioral objective facts, and infringed law and discipline facts. Based on the facts, the special purpose of proof can follow normal procedure to reach facts from the deciding factors and prove existence of the facts. Taiwan's The Code of Criminal Procedure has not identified clearly how lawful methods the evidence applies to and what the recognized procedures should implement and investigate. Lacking of the precise judiciary proceedings on examination, the early stage of developing fact finding does not differentiate the strict investigating procedure on evidence from the general investigating procedure on evidence. This confuses the legal evidential methods with the legal investigating procedures. This article hopes to help provide meaningful opinions on principle of the system of evidence and inner conviction.