Abstract
The spatial characteristics of Thomson scattering in a linearly polarized laser field are investigated. The results show that the electron's motion and spatial distributions of Thomson scattering depend sensitively on the phase η0 at which the electron is injected to the laser field. When η0 equals to 0 or π, the electron motion is a zigzag motion and the spatial distributions of the emission show fourfold or twofold symmetry. In other cases of phases, there is a steady drift motion of electron in the transverse direction, which results in the absence of the zigzag motion and a breakdown of the symmetry of the spatial distributions as well.