Process-based models are effective in addressing spatially explicit dispersal of invasive species based on life mechanisms including birth, death, movement and response to environmental factors. An invading alien species, the western conifer seed bug (Leptoglossus occidentalis), spreads rapidly in the Korean peninsula since 1988. Process-based models were developed to include the rules occurred in population dynamics of the western conifer seed bug population. Passive movements were additionally linked to the models to present local and global transportations due to sapling trades. Simulation results presented the rapid dispersal of the pest species, comparable to field data. Model parameters including the Alle effect threshold and contribution of global transportation were adjusted to reveal spatially-explicit advancement patters of the species. Utilization of process-based models is further discussed in monitoring and management of forest insect pests in field conditions.