The purpose of this study is to compare the management plan for invasive feral domestic cats (Felis catus) population at Mt Dobong, Seoul, Korea. This study compared the effectiveness of euthanasia and trap-neuter return (TNR) for the management of feral cats using a population viability model, based on population parameters obtained at the study site. Among three selected sampling routes (Dobong, Wondobong, Songchu), Dobong region had the highest observation frequency of cats (152 observation), followed by Wondobong (39 observation) and Songchu (26 observation). The super-population size and annual survival rate of adult cats were estimated at 79.18 and 0.61 respectively, from the capture-recapture POPAN model analyses. Annual fecundity was calculated as 2.52 kittens per female. A density-dependent matrix population model was developed to evaluate population viability of two feral cat management programs. The model predicted that the euthanasia of ≥20% or neutering of ≥30% of the effective population (fertile females) would make the population start to decrease. Furthermore, when carrying capacity of the area was higher in the model, the minimum requirement of cats was increased for the population control. However, the model showed that the feral cat population in Dobong region would reach the carrying capacity under current population control management scheme. This suggests that stronger measures of management are required to diminish feral cat populations from Mt Dobong. Since the model used in this study does not include immigration and emigration, further studies should incorporate the effect of those factors in the management of invasive feral cats.