This paper presents the study on orientations interpolation of 6-axis articulated robot using quaternion. In this paper, we propose a control algorithm between given two orientations of 6-axis articulated robot by using a quaternion with spherical linear interpolation. In order to study the quaternion interpolation, We created Inverse kinematics program and Interpolation program using LabVIE$^{(R)}$. The rotation angle of each axis were calculated using both euler orientations interpolation program and quaternion orientations interpolation program. The proposed control algorithm is shown to be effective in terms of motor angles and torques when compared to a conventional Euler angle interpolation, by using both LabVIEW$^{(R)}$ and RecurDyn$^{(R)}$.