There are currently some 500 protesters on the square, and their number is growing.
They are protesting on both sides of the square, without blocking the road.
The protesters are holding the flags of the Regions Party and Ukrainian national flags.
A large stage has been set up with a sign reading "Stop the Crisis" and "The Government Should Resign!"
The rally by the Regions Party supporters was expected to start at noon, with party leader Viktor Yanukovych addressing the protesters.
The Regions Party earlier said around 15,000 protesters would gather on Independence Square.
The party is organizing similar protests in other large Ukrainian cities.