A numerical study was performed to investigate the two-phase flow field in a geometrically simplified swirl cup in a gas turbine combustor. The actual combustor has a hybrid-atomization feature with pressure atomization from the nozzle and airblast reatomization for the liquid film at the tip of venturi wall. The amount of fuel formed in venturi tube could play an important role in characterizing the flow field of this combustor. The present study first investigates the effects of the swirl mode and temperature of the primary and secondary air on the gas-phase flow field and then the effect of droplet injection characteristics in terms of velocity and location on the droplet transport and vaporization behavior. The detailed plots of droplet trajectory are used to identify the size ranges of the droplets which can form a liquid film by their impaction on the venturi tube wall. In general, the results indicate that the droplet injection characteristics have the dominant effect on the cut-off droplet diameter for droplet impaction on the venturi wall.