The new document, which must be approved in a national referendum later this year, provides greater checks and balances, the BBC reported Friday.
"We have gone through a very difficult time and I'm quite sure myself this is the greatest step we have taken so far," President Mwai Kibaki said.
Prime Minister Raila Odinga, Kibaki's power-sharing partner, called approval of the draft constitution a "historic moment."
The proposed constitution provides for greater checks on presidential power and more regional devolution, the BBC said.
It recommends that the president no longer be allowed to appoint judges, and that members of parliament appointed to Cabinet positions be forced to give up their parliamentary seats.