Using mobile robots for exploring unknown areas have been studied for years. Mobile robots are used in different aspects including exploring on the surface of other planets, volcanic zones and even areas which are under construction and dangerous for human. The most important difference among mobile robots is in their locomotion system. Today a variety of locomotion systems are used for these robots and each one of them has its own characteristics. The wheeled drive system and legged system are used widely in different applications. With regard to views of locomotive efficiency and mechanism complexity, the wheeled system is the best option but in terms of the ability to drive on the uneven surfaces, the legged system is the better one. By focusing on the locomotion with the wheel and leg, it seems possible to combine these two and create a new locomotion system called wheel-leg system which has a high efficiency in locomotion and the traverse, particularly on the unstructured terrain. However this new locomotion system will have a higher level of complexity. Since the wheel-leg robots can adapt both their systems of motion for passing rough terrains, they are placed in the category of hybrid locomotive vehicles. In this study, a special type of these robots named six wheel-leg hybrid robotic vehicles is investigated. First, the principal of motion will be illustrated in details and robot’s abilities, the classification of its parameters, and the effects of each of the two wheel and leg system on these parameters will be explained. In the next step, the kinematics equations of the robot on the smooth surface will be driven by removing the effects of legged system and then navigation of the robot to track the specified path will be analyzed. The comparison of the parameters and also the path obtained from the analytical equations with the output of the Adams software will be done. To focus on effects of the robot’s configuration, direct and inverse kinematics equations will be driven at symmetric posture from the vector method and through smooth and rough surfaces. These equations will be validated by comparing the results with the Adams outputs. Eventually, 3D general analytical kinematics equations of the robot will be driven in an innovative way. In this case, the modeling is done by considering the possibility of wheels lifting from ground and without any simplistic assumption. These equations will also be validated at two levels by importing the dynamic model of the Adams into Matlab Simulink. The high effects of longitudinal and transversal slip in results and necessity of introducing motion constraints for the robot redundancy problem are essential points of these equations. Keywords: Robotic vehicle, Hybrid wheel-leg robot, Skid steering system, Redundancy