The charter was approved at a special session of parliament in Pristina
Kosovo's parliament has adopted a new constitution, almost two months after unilaterally declaring independence from Serbia.
The charter pledges to build a state protecting minorities such as the Serbs who vehemently oppose Kosovo's split.
The text is to come into force on 15 June when the UN is due to complete a handover of powers to the new state.
In Belgrade, Serbian Minister for Kosovo Slobodan Samardzic called the charter's adoption an "illegal act".
The new constitution was unanimously approved at a special session of Kosovo's parliament in Pristina on Wednesday.
President Fatmir Sejdiu said the document signalled the fledgling state's commitment to creating an equal society.
"Serbs are the citizens of Kosovo. This constitution is also theirs," he told reporters.
Kosovo is likely to be on the agenda in Russia's talks with the UN's chief
"We want them to be an important foundation and a bridge for the future better relations with the state of Serbia."
The move paves the way for Kosovo to take over from the UN mission which has administered the disputed territory since the end of its 1998-1999 conflict.
The EU will be helping to oversee independence with a 2,000-strong police supervisory mission in Kosovo.
Kosovo's declaration of independence in February has been recognised by almost 40 countries, including the US and most of the EU.
But Russia has stood by its traditional ally, Serbia, in opposing the move.
The charter adoption comes as UN Secretary General Ban Ki-moon makes an official visit to Moscow. Kosovo is likely to be high on the talks agenda.