We studied the effect of altitude and UV-B radiation on biochemical traits and optical leaf properties of Saxifraga hostii. It is alpine perennial plant with narrow leaves forming rosette. We put plates with and without UV filter on two different altitudes: 1095 m. a. s. l. and 1504 m. a. s. l. at the sunny side of Kobariški Stol. The experiment took place during entire growing season. We collected samples in June, August and September. The ground temperature was monitored from first to last sampling. In the laboratory, measurements of chlorophylls (a and b), carotenoids, anthocyanins, UV-A and UV-B absorbing compounds were carried out. Also, the measurements of leaf reflectance and transmittance spectra were performed from 280 to 710 nm. We used one-way ANOVA to examine effect of different temperatures and UV radiation levels on plants and we also examined statistically significant differences. The results were compared within one sampling. We examined the effect of altitude and UV radiation level and their interaction on individual biochemical and optical properties of chosen plant with two-way ANOVA. There was no effect of observed environmental factors on content of UV absorbing compounds, which implies plant’s adaptation to UV radiation. There was no effect of temperature and UV radiation level on chlorophyll a and b, carotenoids and anthocyanins content in August, but there was some effect on those pigments in September, which implies early senescence. UV radiation interacts with other environmental factors therefore plants, exposed to different environmental factors on two different altitudes respond differently on UV radiation.