The NOAA has posted a film loop of China at night, from 1992 to 2010.
Here is their photo from 1992:
It is interesting to look at the countries surrounding China as well. Japan is nearly unchanged, but was lit up like a Christmas tree to begin with. India and the countries of South East Asia show moderate improvement. South Korea became an explosion of light in those years, especially around Seoul. North Korea is nearly in complete darkness in both photos.
(Note that the areas north and west of China are sparsely inhabited, so it would be odd to see many lights there.)
(H/t Business Insider)