Concentrations of total nonstructural carbohydrates (TNC) and of total nitrogen (N) were determined in June, July, August, November 1990 and June 1991 in rhizomes of Phalaris arundinacea in the Hrubý Jesenik Mts (The Sudeten, The Czech Republic). The stands were situated at two altitudes: (1) at the altitudinal maximum of P. arundinacea in Malá Kotlina cirque (1150-1350 m a.s.l.); (2) in the foothills at Malá Morávka village (700 m a.s.l.). The TNC and N concentrations in rhizomes were the same at both localities. The TNC concentration varied during the year, a minimum occurred in June and maximum did in November. The minimum nitrogen concentration was measured in August while its maximum was in June. The stands in the Malá Kotlina Cirque were subjected to the following treatments: (1) no cut, (2) cut in June, (3) cut in August, and (4) cut both in June and August. The cut plants stored less TNC and N in comparison with uncut ones. A more severe reduction in the rhizome content of TNC and N was found in plants cut in August and in plants cut both in June and August.