This paper presents the development of an autonomous Sit To Stand (STS) motion using NAO robot. NAO robot hip limitation will emulate the limitation faced by people having STS problem. To perform the motion, three main steps have been developed (1) horizontal distance identification, (2) joint angle determination, and (3) stability control. This step was developed based on Alexander STS technique. Results show that NAO robot is able to achieve halfway stand up from chair height between 9.6 and 12.7 cm automatically. The robot's best performance is at 12.7 cm height with swinging time of 0.52 s in experiment and 0.2914 in simulation. The developed system will contribute to the development of exoskeleton, rehabilitation and evolution of humanoid robot. This system also enhances NAO's ability for medical study on STS motion or as tools in searching for the best chair design. © 2014 Springer Science+Business Media Singapore.