1. A method of controlling a walk-assistive robot, the method comprising: obtaining, via a sensor, a ground data regarding a terrain; creating, via a controller, ground information based on the ground data, the ground information including information associated with both a reference ground terrain and a comparison ground terrain located in at least two of a forward direction, a rearward direction, and a sideward direction with respect to a walking direction of the walk-assistive robot; determining, via the controller, which of a plurality of ground shapes represents the terrain such that the controller determines that the comparison ground terrain is one of uneven ground, stair ground and inclination ground by analyzing differences between the comparison ground terrain and the reference ground terrain; determining, via the controller, a control patterns of the walk-assistive robot by analyzing the ground information such that the controller determines the control patterns of the walk-assistive robot according to the determined ground shape; and controlling, via the controller, the walk-assistive robot based on the determined control patterns such that an amount of assistance provided by the walk-assistive robot varies based on the terrain.