In this paper, the kinematic structure of the geared robotic mechanism (GRM) is investigated with the aid of two different methods which are based on directed graphs and then these methods are compared, accordingly. One of the methods is Matroid method developed by Talpasanu and the other is Tsai-Tokad (T-T) graph method developed by Uyguroğlu and Demirel. The findings show that the kinematic structure of the geared robotic mechanism can be represented by directed graphs and angular velocity equations of the mechanisms can be systematically obtained from the graphs. The advantages and disadvantages of both methods are demonstrated in relation to each other.