Jurors do not search out the evidence; neither do they seek out the law that is to be applied to the case. Rather the trial judge instructs them about the legal principals that are relevant to the case. These instruction are a crucial part of a trial. Jurors may reach erroneous verdicts because they ignore the law or do not determine the facts correctly, but errors are inevitable if the jurors do not understand the applicable law. But, even with better methods of presenting jury instruction, they will not be completely understood. Surely, this is a weakness in jury system, but its detrimental effects can be overstates. In fact, it is worth repeating that judges generally agree with juries' verdicts, and when they differ, judges usually ascribe the conflict to differing views of the evidence. Whatever conceptions of the law jujors use to decide cases, their notions typically coincide with those of the judges. About all, the jury system currently fulfills its funtions - not perfectly, but very well. It could serve them even better if the evidence presented to juries were improved. If we make jury instruction better, and jury verdicts will be better. Yet, despite this truth, that individual jurors do not judge the evidence has been a constant complaint. So, many people concludes that it is neither truth nor justice but jury selection that decides the case in America. As the efforts to improve witness identification procedures indicate, entrenched attitudes and practics with an objective consideration of reform and hinder the adoption of necessary improvements. Methods for institutionalizing jury instruction need to be found. So, it is necessary to rule jury instruction clearly in the connection with court-oriented Trials. It is time that a device on the jury instructions must be discussed to exercise the social justice. I think that the law must be enforced to be more efficiently and consistently through the testimony of a person and jury system in a criminal proceeding. In this context, Jurors have a strong sense of responsibility for the realization of nation-wide wishes for clean society through jury instruction.