The effects of a cross-magnetic field on preparing thin films by pulsed Nd/YAG laser deposition have been investigated. Two-dimensional emission profiles of the plasma plume were detected with an ICCD camera, and the shape of the plasma plume in the cross-magnetic held was changed. The density of the droplets on the substrate in the cross-magnetic field decreased in comparison with those in a non-cross-magnetic field. These experimental results suggested that a high-quality and large-area uniform thin film can be prepared by using a cross-magnetic field.