Important areas of semi-natural grasslands are affected by abandonment in Apuseni Mountains, situation that leads to a series of specific negative aspects. Semi-natural grasslands pass through certain successional stages, materialized by different types of grasslands. The aim of our study was to follow the successional stages of Agrostis capillaris L.–Festuca rubra L. grassland type, as a result of abandonment. The study included 27 grasslands with similar site conditions. There were three different categories of abandoned grasslands: abandoned up to 5 years, abandoned between 6 and 10 years, abandoned more than 10 years. The categories of abandonment caused changes at the level of phytocoenoses, registering a degradation of the vegetation from both, agronomic and ecologic point of view. The semi-natural grasslands, situated on sites with different disadvantages (defectuous orography, reduced trophicity, pronounced acidity, etc.) which are on the threshold to be abandoned, or are already abandoned, need to be mowed at least once at four or five years, to preserve their specific floristic structure.