The analogy of the investigation is one of the most of important investigational methods at the fundamentalists. The research came upon three researches in the first dissertation. I issued the meaning of investigational analogy in language that means to request the evidence and in the structures, it has four meanings: one of them investigation in the sense of analogy and it has images and one of the most important is the opposite analogy and the evidence analogy. Then, I spoke about the proof, some say that it is not more than a proof, and others said that it is not a proof. In the second research, 1 spoke about investigation analogy and its effects on the jurisprudence branches. 1 set some applicable examples to the contrast analogy in the jurisprudence branches : one of them stipulations of fasting for the validity of seclusion and also some applicable examples for the evidence analogy in its jurisprudence branches: one of them the verdict of prayer on the martyr.