Abstract
Astrometry is the most direct and accurate method to reveal the 3D structure of the Milky Way. I review the Galactic structure based on VLBI astrometry results. First, I introduce some basic concepts of VLBI astrometry and actual VLBI arrays. Then, I show some recent scientific results with VLBI astrometry, namely (i) Fundamental parameters of the Milky Way, (ii) The rotation curve of the Milky Way, and (iii) The Perseus (main) arm of the Milky Way. Finally, I briefly describe future prospects for gas and stellar astrometry in the Gaia era.
