Neogene Karlovo Basin, Central Bulgaria was comparatively studied with other Bulgarian lignites for palaeoenvironment assessment. Petrographic and chemical methods were used. The data allowed floral reconstruction at the region and assumption for the climate during the corresponding geological time. The data of geochemical and petrographic studies gave proves for the long-term evolution of the Late Neogene on the South Eastern Europe connected with the decrease in palaeotropical elements and increase in arctotertiary taxa. Conifers remained main coal-forming vegetation predominantly represented by Pinaceae. Biomarker assemblage assumed insignificant Cupressaceae/Taxodiaceae contribution. Monoaromatic angiosperm-derived triterpenoids with ursane/oleanane skeleton proved the presence of dicotyledonous angiosperm-derived organic matter in the palaeoplant taxa as well. Palaeoenvironmental conditions within the forest swamp should be determined as limnic, with varying water table and seasonal drying.