We studied the vegetation of grasslands on the Sár Mountain, in Gyöngyös. The areas are mowed regularly by the Bükk National Park and mechanical shrub control was done as well. The effects of these habitat management techniques were investigated on grasslands of different degradation levels. Coenological studies were made between May and June in 2013 with 2×2 m relevés. The study areas were characterised according to nature conservation value categories and life forms. Our results showed that the above mentioned management techniques had positive effects on the diversity of grasslands. On the managed grasslands the abundance of woody species decreased, while the abundance of annual and perennial grass species and dicotyledonous herbaceous species increased. The highest species number (58-78) was recorded in the case of control areas. The number of species was high (47-49) in the areas managed by mowing and mechanical shrub control. The lowest species number (43) was recorded in the areas which were not mowed after mechanical shrub control. According to the nature conservation value categories the number of protected species was the highest in the control areas. Our results approved that regular mowing is needed after mechanical shrub control to sustain the diversity of abandoned grasslands in the long run.