1. Institute of Biology and Soil Science, FEBRAS, Vladivostok 690022, Russia; 2. Research Center of Paleontology & Stratigraphy, Jilin University, Changchun 130026, China; 3. Key-Lab for Evolution of Past Life Environment, Ministry of Education, China, Changchun 130026, China

The palynological assemblage from Wulaga dinosaur site in Jiayin from southeastern Zeya-Bureya Basin was studied. The high content of pteridophytes spores is characteristic for this assemblage. The further characters are in decrease of abundance-tricolpate pollen, Ginkgocycadophytus, pollen of Taxodiaceae, Cup ressaceae and Taxaceae ( TCT) , bisaccate pollen of Pinaceae, and triporate pollen. The bone-bearing burials of Wulaga dinosaur site formed under conditions of vast swampy river valley covered by ferns and taxodialeans. Tricolpate pollen, produced by plants, close to those of Platanaceae, Fagaceae, Betulaceae, and Juglandaceae, counts in favor of valley river open canopy forests.