  Decay property of hidden-charm tetra-quark mesons is studied. It is seen that
estimated width of iso-triplet odd $\mathcal{C}$ partners of X(3872), although
still crude, is compatible with the measured ones of Z_c(3900). It is pointed
out that confirmation of an eta-pi^0 peak around 3.2 GeV indicated in
gamma-gamma collisions gives a clue to select a realistic model of multi-quark
mesons.
