Failure strength evaluation on resistance welding mixed adhesive bonding was studied. Tensile-shear tests were carried out with the single-lap specimen, using both resistance welding and adhesive bonding. Peel tests were also carried out with DCB specimen. Composites were manufactured using the polyester as a matrix and bamboo natural fiber layer as a reinforcement. Adhesive bond, having bonding strength that remains unaffected by heat at resistance welding, were selected. Generally, adhesive bond require a long curing time and have little strength before hardening. Resistance welding helps weakness of adhesive bond both curing time and peel strength. And the spew fillet of adhesive bonding also helps to release stress intensity of edge of joining. The failure mechanism was discussed in order to explain higher peel and tensile-shear strength of resistance welding mixed adhesive bonding.