The Purple Mountain Observatory was built in 1929 and completed in 1934. It is situated on the Purple Mountain in the eastern suburb of Nanjing.

The programs in astrophysics consists of solar physics, planetary physics and high energy astrophysics; and that of celestial mechanics deals mainly with orbital theory of artificial satellites, the dynamical evolution of the solar system, calculation and compilation of almanacs. In addition there are routine observations on asteroids, comets, artificial satellites, sunspots, solar flares spectra, spectroheliograms, solar radio radiation and certain special celestial phenomena as well.