It is considered that three identical two-level atoms are separately trapped in three coupled single-mode optical cavities, and each atom resonantly interacts with cavity via a one-photon transition. The tripartite entanglement dynamics among atoms is studied. The influence of cavity-cavity coupling constant on the tripartite entanglement among atoms is discussed. The results obtained using the numerical method show that the tripartite entanglement among atoms has a nonlinear relation with the cavity-cavity coupling coefficient. On the other hand, the three-body entanglement is the result of the coherent superposition of the two-body entanglements.