This paper presents an approach in assisting a Sit-to-Stand movement using a robotic walking support system. In general, robotic walking support system is used to provide walking stability. We will extend its function to assist a user in executing a Sit-to-Stand movement. The first approach will be called passive support. In this approach, the support system will be stationary as the user execute the Sit-to-Stand movement. The knee torque will be determined and this will be compared to a Sit-to-Stand movement without support. The second approach will be called active support and the knee torque will be supported. A motion control algorithm will be proposed such that the support system will move based on the supporting torque. The actual experimentation on both approaches in assisting a Sit-to-Stand movement will be presented. The experimental result on active support shows the validity of the proposed motion control algorithm.