We introduce the collective behavior of the infinite-particle Cucker-Smale model with discrete form and kinetic form respectively. For discrete form C-S model, we first establish the boundness of velocity by showing the non-increase of the supremum norm of velocity through classifying the particles according to the norm of velocity, and then obtain the flocking behavior of infinite-particle Cucker-Smale model. More precisely, the solutions will concentrate exponentially fast in velocity to the average of the initial velocity, while in space the position differences between particles will be uniformly bounded. While for the kinetic form C-S model, we focus on the formation behavior of the kinetic C-S model with initial datum not compactly supported in position field. First, we obtain the existence and uniqueness of the classical solutions to the kinetic C-S model by standard approximation method. Second, by using the characteristic flow, we overcome the difficulty of weakening the attraction between particles caused by the non-compact position support through some estimates and establish the formation behavior of the classical solutions to the kinetic Cucker-Smale model, which means the consensus of velocity。
