Beyond the conventional meson and baryon, exotic states may exist. In fact, the existence of the multiquark configuration was suggested by Gell-Mann and Zweig at 1964 and Jaffe at 1977. Until 2003, Belle collaboration discovered X(3872), maybe as the first prototype of such kind of particles. Consequently, many interpretations were proposed, e.g., glueball, molecular, or just the excited charmonium state. Later, a series of such candidates (called XYZ) are observed in experiment, e.g., the established Y(4260), Y(4360), and Y(4660); Zc(3900) [7 sigma significance], Zc(4020), Zc(4430), and Zb(10610) listed in the 2018 version of Particle Data Group. However, the hot dispute between LHCb/CMS/CDF and D0 collaboration on the evidence of X(5568) resonance remains. Combined with the recent discovery of the pentaquark states Pc(4380) and Pc(4450) by LHCb collaboration, this research area becomes more attracting. Besides, on the experimental side, Belle-II is running and the super tau-charm factory is enthusiastically discussed in China, with increasing luminosity by two orders of magnitude compared to BESIII. This situation provides huge opportunity for our better understanding of the hadrodynamics.

In this special issue, we aim to attract regular papers as well as the review related to such topics on the exotic hadron candidates and also decay of heavy flavored hadrons. Both theoretical and experimental papers are welcome:

Potential topics include but are not limited to the following:

• Spectroscopy of mesons and baryons
• Decay property of heavy flavored hadrons
• Exotic hadron candidate—XYZ states
• Hadronic structure—form factor, reaction, production and decay
• Application of effective field theory, dispersion theory, Bethe-Salpeter equation, and other nonperturbative tools to treat final state interaction
• Dibaryon, few-body nuclear physics