Today, in Europe and the world, several projects for the ring-based synchrotron light source are going on, aiming to generate the high brilliance synchrotron light by the low-emittance beams. One of the critical issues for such a high-quality beam is the beam dynamics that handle the beam optics and realize the low-emittance beam by keeping sufficient beam stability by the optics design. On the other hand, it is also essential to evaluate precisely the beam quality and stability for such a high-quality beam by beam diagnostics. This workshop aims to prepare the opportunity to discuss the beam dynamics and diagnostics for the low-emittance and high-quality beam and share the possibility and requests from both sides. One of the workshop’s goals will be to make clear the directions of the beam dynamics and diagnostics for the low-emittance rings.