The kinematic space could play a key role in constructing the bulk geometryfrom dual CFT. In this paper, we study the kinematic space from geometricpoints of view, without resorting to differential entropy. We find that thekinematic space could be intrinsically defined in the embedding space. For eachoriented geodesic in the Poincar\'e disk, there is a corresponding point in thekinematic space. This point is the tip of the causal diamond of the disk whoseintersection with the Poincar\'e disk determines the geodesic. In thisgeometric construction, the causal structure in the kinematic space can be seenclearly. Moreover, we find that every transformation in the $SL(2,\mathbb{R})$leads to a geodesic in the kinematic space. In particular, for a hyperbolictransformation defining a BTZ black hole, it is a timelike geodesic in thekinematic space. We show that the horizon length of the static BTZ black holecould be computed by the geodesic length of corresponding points in thekinematic space. Furthermore, we discuss the fundamental regions in thekinematic space for the BTZ blackhole and multi-boundary wormholes.