Personal robotics is a new and attractive use of robotic technologies. In this paper we study one of its important topics—real-time motion planning of personal robots. We propose to use primitive motions and their combinations to make this possible. The primitive motion has a unified pattern and is borrowed from the motion pattern of human hands observed by previous researchers. The pattern is simple yet powerful and can form complex trajectories. A reflexive motion control scheme is proposed to activate appropriate primitive motions for a desired motion. As a result, real-time motion planning of personal robots becomes possible by using discrete and sparse human commands. Experiments results are presented to show the effectiveness of the proposed scheme.