Comparison was made between the fluorescent lamp and the incandescent lamp basing on qualitative experiments, and the following conclusion was reached. (1) In incandescent lamps when the reflection factor of the color of reflector is smaller, intensity of illumination will be so much the lower. The same tendency is seen with fluorescent lamps, but the effect is generally smaller as compared with incandescent lamps. Furthermore, when the color of reflector belongs to the same color group as the dominant wave-length of the light-source, intensity of illumination will be stronger. In case it is of the complementary hue or of the same color group, illumination comes out weaker. (2) When various artificial light-sources are mutually compared by the quantities of filtered radiation, it is found that the light of daylight and white fluorescent lamp resembles most closely the daylight in cloudy weather. In incandescent lamps, the zone of long wave-length is in excess, while the blue and violet zones can hardly be seen. (3) Even among the persons with normal sense of color, a high percentage of misreading and hard-reading of Stilling's Charts occurs under the illumination by an incandescent lamp, whereas under that of a white fluorescent lamp, the percentage is extremely lower. (4) As the color rendition of various light·sources are examined from the viewpoint of the "difference of color", de luxe daylight fluorescent lamp is most superior. Next comes de luxe white fluorescent lamp, and it further worsens in the order of the daylight fluorescent lamp, white fluorescent lamp, fluorescent filament lamp, and daylight lamp. Ordinary electric lamps are markedly inferior. However, daylight fluorescent lamps are entirely the reverse of ordinary electric lamps in their status of the "difference of color". (5) Although the fluorescent lamp is an artificical light-source superior to the incandescent lamp in both quantitative and qualitative aspects, they should be utilized to their best advantage respectively so as to conform to the use intended.