The red fluorescent transgenic mouse has given us a promising insight into regenerative medicine. Each organ of this animal has already been investigated by the method of using a fluorescent imaging system, but not by histological methods. First of all, we compared all the organs of the red fluorescent transgenic mouse with previous studies using enhanced green fluorescent protein (EGFP) mice by the IVIS Luminal Imaging. Next the expression levels of each organs mRNA was measured by RT-PCR. Further, the histological sections of the red fluorescent transgenic mice (7 days after-birth) were taken by light microscope. The results of the three methods were compared and the following findings were made ; We found a discrepancy between the fluorescent imaging method which was used in past reports and the expression levels of mRNA and multiple discrepancies between these and the histological observations. Explaining the discrepancies was beyond the scope of this experiment. We thought that two or more methods including the histological examination were reguired by future research and verification. The red fluorescent transgenic mouse was more useful than the EGFP mouse in the fluorescent expression of the hepar, spleen and ren. All of the organs in the red fluorescent transgenic mouse have a strong fluorescent expression. We hope that these red fluorescent transgenic mice are used in the research of regenerative medicine and the metastic route of the tumor stem cell.