Metals and plastics have been used in several industrial applications such as automobiles, electronic devices and aircrafts. The joining of their dissimilar materials is one of key technology in manufacturing. Direct joining of metal and plastic with laser has many advantages over the conventional bonding methods with adhesives or the mechanical fastening with bolts and nuts. In this study, direct joining of pure titanium and Polyethylene terephthalate (PET) was carried out with a LD laser beam in infrared wavelength. The mechanical properties after directly joined were evaluated by a tensile shear test. In the tensile shear test, after adjusting properly the welding conditions, fracture occurred through the base PET with sufficient elongation over the yield point of PET. TEM (Transmission Electron Microscope) image and the EDS (Energy Dispersive X-ray Spectrometer) analysis at the jointed interface demonstrate that the titanium and the PET are tightly bonded on nano-meter sized level through the titanium oxide film. Moreover, it was found that, as laser absorption increased with increasing thickness of Titanium oxide, LAMP joints improved its strength within high welding speed region in spite of leading to get brittle.