An investigation was conducted in a 1.5 hm² plot of Picea asperata-Abies nephrolepis forest to determine the tree species, DBH, treefalls direction, level of decay and microsites characteristics of pit and mound complex formed by 36 uprooted treefalls from June to July, 2013. The plant species, their height, abundance, cover on the sites were measured; their importance value and richness in the P. asperata-A. nephrolepis forest were calculated. The results showed that: 1) all uprooted treefalls are composed of four tree species. The frequency of tree species forming pit/ mound complex decreased in the order of A. nephrolepis (54.1%), P. asperata (27%), Betula platyphylla (13.5%), and Pinus koraiensis (5.4%). 2) Twenty-nine of the 36 uprooted treefalls were located in the north direction. 3) There was significant, positive correlations between pit volume and pit width, between pit volume and mound height, between pit depth and mound thickness; there were significant, positive correlations between mound volume and its superficial area, between pit volume and its superficial area. 4) At three microsites, species richness, Pielou evenness index, Simpson eco-dominance index, Shannon index decreased in the order of intact site, pit bottom, and mound top. 5) The importance value of Rubus sachalinensis was the biggest on mound. Pit bottom was beneficial to the growth of Urtica laetevirens and Impatiens nolitangere. 6) Species richness on mound top and on pit bottom was the biggest when level of decay of uprooted treefalls was level Ⅱand level Ⅴ, respectively. Average total coverage of plants and their average density were in the sequence of intact site > mound top > pit bottom.