The aim of this work was to determine the intensity of nitrogen mineralization in forestry drained ombrotrophic peatland soils in the Stołowe Mountains National Park, SW Poland. Additionally discussion about the shallow organic soils classification according to Polish Soil Classification (2011) is presented. For the study three research transects were established on forestry drained ombrotrophic peatlands in the Stołowe Mountains. Each of the transect consisted of four (site A and B) or five (site C) sampling plots. Sampling was conducted in the year 2012. The soil samples for the basic soil properties analysis were sampled in April, whereas undisturbed soil samples were collected in stainless steel rings (100 cm3) every 10 cm in April (spring), July (summer) and October (autumn) to show the seasonal dynamics of nitrogen mineralization. Statistical analysis showed that the content of N-NH4 was mainly determined by actual soil moisture and precipitation rate, whereas the content of N-NO3 was positively correlated with air temperature. Among investigated peatlands the highest concentrations of mineral nitrogen forms was observed in the Długie Mokradło bog, situated on the Skalniak Plateau-summit. Additionally, the results obtained showed that implementation of new subtype: shallow fibric peat soils (in Polish: gleby torfowe fibrowe płytkie) within the type of peat soils (in polish: gleby torfowe) should be considered during developing of the next update of Polish Soil Classification.