Palaeobotanical and palynological data were analysed from the Mississippian localities of the north-western part of Russia. The distribution of various fossil plants in the studied area has been traced. The palynological assemblages were described and palaeoecologically analysed. Arborescent lycopsids played the main role in the palaecommunities. Arthrophytes did not significantly influence the composition of the assemblages under study. Pteridosperms dominated only in repopulate disturbed areas. It has been demonstrated that the forest mire vegetation type dominated during all studied time intervals while the non-forest mire gradually diminished. Palaeoecological interpretation of palynological data is generally supported by palaeobotanical data.