The impact of sanitation cutting after massive secondary forest dying on the aboveground biomass production of Calamagrostis arundinacea was investigated in the Spiš part of the Slovenské rudohorie Mts (a communal forests of the Nálepkovo village). The values of biomass ranged in the interval 36.16 to 1417.91 g.m-2. Higher solar input and the development of new disengaged stands after sanitation cutting were the most important factors, which influenced increase of the Calamagrostis arundinacea aboveground biomass.