Laser straight cutting of titanium alloy is carried out. Thermal stress fields in the cutting section are examined using the finite element numerical code. The morphological changes in the laser cutting region are investigated using optical microscopy, scanning electron microscopy and x-ray diffraction technique. It is found that von Mises stress attains high values in the vicinity of the top and bottom surfaces as well as at the mid-thickness of the workpiece. Some small sideways burns in the cut section are observed, which are associated with the high temperature oxidation variations during the cutting process. Due to the brittle structure in the re-cast layer, a few locally scattered microcracks are observed at the re-cast layer surface.