Recently, the number of elderly people is increasing very much especially in Japan. It is one of the most important theme to maintain and improve their QOL(Quality of Life) and it is necessary that elderly people can do their activities in daily lives according to their intention. Because the walking ability is indispensable in their social activities, gait assist canes are often used to support them and the demand for canes is increasing as the growing number of elderly. However, generally used canes (single or multi-legged cane) have the instability and the danger of falling on the uneven terrain. So, we will propose ``Gait assist robotic cane'' which can absorb irregularities on the uneven terrain and can keep the balance automatically. This cane can change the length of each leg according to the contact condition and control compliance of supporting legs using MR fluid. In this paper, we developed a prototype robotic cane which could be actually used outdoors and the control algorithm for the step absorption and the balancing functions. In the experiment, it was confirmed that the step absorption and the balancing function were effective.