Amagnetic field was incorporated into pulsed laser deposition of diamond-like carbon films. Due to the collision of neutral carbon atoms with energized electrons in the plume, more carbon ions were generated. As aresult, the hardness of the diamond-like carbon films was increased in comparison with the hardness of those deposited without amagnetic field. In order to confirm this mechanism, the plume current was measured. As expected, the plume current was increased considerably (about two times larger than that without the magnetic field). It is known that the collision probability is proportional to the magnitude of the magnetic field. So we can expect that astrong magnetic field should be more beneficial to the deposition of harder diamond-like carbon films. Our experimental results were in agreement with the prediction. Much harder diamond-like carbon films have been obtained under astrong magnetic field.