This paper presents the new gait implementation of a biped robot with smooth walking using 3-dimensional continuous trunk motion and kick action of ankle joints. Trajectory generation ova trunk is performed not on a unit gait but on a whole walking interval. In applying kick action such as heel-touch or toe-off, varying coordinate system was employed for the simplification of the kinematic analysis. Desired ZMP (zero moment point) is also changed to implement the efficient kick action. As a result, balancing motion of the proposed gait was much more decreased than that of conventional one. Moreover, robot\`s walking behavior is very smooth, natural and similar to the pace of a human. The walking experiment system is composed of eight AC servo motors and a DSP controller. The walking simulation and the experimental results are shown using the proposed new walking algorithm.