Abstract: Plants have evolved on the earth’ surface together with human beings, and then they depend on each other like a friend. Plants produce many different types of sunscreens. Some of these are physical sunscreens (trichomes) to reflect UV-B and some are chemical sunscreens (anthocyanins) to absorb UV-B. The high level UV radiation can increase trichome density and anthocyanin content. On the other hand, plants’ leaves in the high level UV radiation have high concentration of absorbing pigments. In this work, the absorbance spectra and the light harvesting efficiency (LHE%) of absorbing pigments extracted from the leaves of pink-flowered rain tree (Samanea saman) at sea level and at 1200 m above sea level, have been studied by UV-VIS spectroscopy to protect the effects of UV attack. According to the absorbance spectra, two plants can absorb nearly 100% of UV-A and UV-B, and the absorbing species in higher elevation plants are more concentrated than that in lower elevation plants.