Induced flow and motions of fine solid particles with irradiation of YAG laser beam in water droplet, often called laser trapping, are discussed in this paper. A micro-sized heat spot could be produced by the absorption of the laser beam, and heat transfer occurred from the heated glass plate to the water droplet with the particles. The local flow was induced by the effect of the heat transfer. These interesting phenomena were observed under microscope and recorded by a VHS connecting to a CCD camera. The particles were rotated with the irradiation of the laser beam, the revolution was too high compared to the VHS capture rate. The theoretical backgrounds on the induced flow and the motion of the fine particles are also discussed.