Yushania niitakayamensis (Hayata) Keng f. is a member of the bamboo subfamily (Bambusoideae) of the grass family (Poaceae). The species is distributed in Southeast Asia. In Taiwan, it is distributed at altitudes around 1000-3600 m. The species appears to spread mainly by rhizomes and flowers rarely. It is a dominant species in alpine meadow and has a percent coverage above 90% in the grassland community. The floristic composition is different between inside and outside of Y. niitakayamensis stand. Pot experiment showed that the soil sampled from the stand showed inhibitory effect on the growth of lettuce, Biden pilosa, Miscanthus transmorrisonesis. The elements of soil sample collected from outside and inside of Y. niitakayamensis stand were analyzed by Inductive Couple Plasma/Mass Spectrometry. The concentrations of Na, Mg, Si, K, Fe, Cu, Zn, Pb in the inside soil was higher than the outside soil. The concentration of Ca was significant higher in outside soil. The phytotoxin also was found in ethyl acetate extract of the inside soil. The result indicates that Y. niitakayamensis as a dominant species could significantly change the chemical composition of the soil.