It is important to generate an appropriate traj ectory in task space in the traj ectory planning of industrial robots. Many industrial robots blend linear and circular traj ectories in their traj ectory generation with several advantages. However, it does not provide a detailed method for the smooth motion of position and orientation of the blending traj ectory. This study proposes a circular path based traj ectory blending algorithm considering time synchronization of position and orientation of the blending traj ectory. This algorithm can generate a more smooth and natural motion by matching the duration time of position and orientation of the blending trajectory using a simple geometric shape based equations. The proposed algorithm was evaluated using a 7 DOF industrial manipulator. The experimental results show that the proposed algorithm can operate stably for various cases.