Juntai Shen is a Distinguished Professor at the Astronomy Department of Shanghai Jiao Tong University. He obtained his PhD in Astronomy from Rutgers University in USA in 2005, he then worked as a Harlan J. Smith Postdoctoral Fellow at the University of Texas at Austin from 2005 to 2009, and a Bairen research professor at Shanghai Astronomical Observatory, CAS from 2009 to 2019. His research covers a wide range of topics in galactic dynamics, including barred galaxies, galactic warps, dynamical modeling of the Milky Way bulge and its exotic X-shaped structure, and measuring the mass of supermassive black holes in elliptical galaxies through dynamical modeling. Many of his papers have been highlighted by international textbooks and prestigious reviews. He has also been invited as an expert reviewer for various funding agencies worldwide.As the expansion of the universe continues to accelerate, the internal secular evolution of galaxies becomes more important as the distance between galaxies generally increases. The largest galaxies in the local group provide an ideal laboratory due to their proximity to study the secular evolution processes driven by internal dynamical structures, such as a bar and spiral arms. I will review the key dynamical properties of local group galaxies, how they are distributed along the Hubble sequence, the signatures for ongoing secular evolution, and in turn how we may infer the dynamical properties of a central bar from such signatures.  Recent attempts in dynamical modelling of barred galaxies based on stellar and gaseous kinematics are also discussed.