Crowds marched to the Prime Minister Abdel Rahim al-Kib's office from Tripoli's landmark Martyrs Square where they had gathered early on Sunday.
The Berbers want to be represented in the new cabinet and their rights and language, Tamazight, to be officially recognised.
"We didn't call for something new here," said Mazigh Buzakhar, an activist for the Anazigh community who was at the demonstration. We are just going to call for our basic human rights.
We are still going to demonstrate, we are still going to use the media. We are still going to use our civil society organisation to push and put pressure on the new government to recognise Tamazight in the new constitution."
The Berber have been present in Libya since before the Arab conquest in the seventh century, and are remembered for their military resistance to the Italian occupation which ended 60 years ago.
The vast majority live in the northwestern Nafusa mountains, in Zuwarah region 120 kilometres west of Tripoli and in Ghadamis province on the frontier with Algeria.
They are also angry after being active from the start of the revolt against former leader Colonel Kadhafi when they worked with the Arabs to topple the regime.