Front vehicle body structure includes left and right front side frames, a subframe provided on the undersides of the side frames, and left and right mounting brackets for connecting the side frames and subframe. Engine-transmission unit is mounted on the subframe. Respective rear half portions of the side frames extend toward the rear of the vehicle body while gradually approaching the centerline of the vehicle body. Left and right mounting brackets are provided, on the respective rear half portions, to project toward the centerline. The left and right mounting brackets are detachably connected to the subframe. When an impact load greater than a predetermined intensity has been applied, the left and right mounting brackets are detached from the subframe and then squashed by the engine-transmission unit while effectively absorbing the impact.