Planetary nebulae (PNe) are descendants of the low- and intermediate-mass stars, which account for the absolute majority of stellar populations in the universe. As an important category of the interstellar medium, PNe are one of the few classes of celestial objects that are active in every part of the electromagnetic spectrum; they have proven to be ideal laboratories to study various astrophysical processes and excellent tracers of the chemistry, dynamics, and stellar populations of their host galaxy. Today the more in-depth investigation of PNe requires cutting-edge instrumentation (e.g., IFU, AO). I will give a talk based on my recent work on PNe using the world- class telescopes, including the Hubble Space Telescope (HST), the 10.4m Gran Telescopio Canarias (GTC), and the 3.6m Canada-France-Hawaii Telescope (CFHT).