“…[1,2]). For the low energy region where the abnormal states showed up, nonperturbative QCD should be explored, such as Lattice QCD [3][4][5][6], QCD sum rule [7][8][9][10], effective field theory [11][12][13], Dyson-Schwinger equations [14][15][16], chiral quark model [17,18], chiral unitary approach [19][20][21][22][23], and so on. Chiral dynamics for meson-meson and meson-baryon interaction has played an important role in understanding the nature and structure of hadronic resonances, and it has shown that many known resonances are generated dynamically as a natural consequence of the hadron-hadron interaction, much as the deuteron appears as a simple bound state of a proton and a neutron.…”