During 2010 and 2011, seed predation and removal of Mongolian oak (Quercus mongolica) were studied in the City forestry demonstration base of Northeast Forestry University, Harbin, Heilongjiang Province. The results showed that: there was no significant difference in Mongolian oak seed predation rate among the two years. But Mongolian oak seed removal rate in 2010 was significantly higher than 2011, and the remaining rate was significantly lower than that of 2011. The total seed predation rate and removal rate of Mongolian oak by rodents respectively were (5.7±13.5)% and (27.1±37.1)%. Mongolian oak seed predation rate and removal rate were the highest in scotch pine forest because of predation and removal. Seed remaining rate was the highest in Manchurian walnut forest. Mongolian oak seed predation rate had not significantly different in 0m, 10m, 20m, 30m, 40m, 50m distance group that were apart from edge of Mongolian oak forest, but removal rate and remaining rate had significant difference in 2010. Seed predation rate had significant difference at different distance group, removal rate and remaining rate had not significantly different in 2011. Mongolian oak seed predation rate was the highest at 20m. There were (37.8±49.7)% and (27.7±49.8)% Mongolian oak seed were used by rodents in 2010 and 2011, respectively. This showed that the rodents were the main ground seeds predators of the City forestry demonstration base, winter food shortages and autumn storage seeds could be the main reason that caused Mongolian oak seed have large predation and spread stress by rodents. Therefore, seed predation and removal of Mongolian oak by rodents could affect the fates of Mongolian oak seeds and population regeneration.