Noninvasive techniques for the measurement of biomedical information are the most desirable for diagnostic purposes. The use of optical methods in biomedicine, for example, is rapidly emerging with potential applications. Photo-plethysmography (PPG) is a simple optical technique to examine the state of heart and blood circulating system in situ. Conventionally, wavelength region covering from red to near-IR, commonly referred to as the therapeutic window (600nm-1300nm), have been used for PPG. In the present study, we developed a simple photometer for PPG that used lasers as light sources and compared the pulse blood flow in finger tip at ten different wavelengths from 476.5nm to 820nm. The ratio of the amplitude of ac components to dc components of transmitted light through the tissue was measured as a function of wavelength. Our results suggest that blue and green wavelength regions are also useful for PPG as the red and near-IR regions.