The southern Sudanese leader has returned to his base, the remote town of Rumbek, for the first time since signing a historic peace deal.
Garang stepped over a cow slaughtered in his honour
John Garang received a rapturous welcome after flying into the town.
Mr Garang led southern rebels against the government in Khartoum in a bloody civil war until the peace agreement was signed in Kenya earlier this month.
His organisation, the Sudan People's Liberation Movement (SPLM), is now expected to formally ratify the deal.
It will then begin the task of putting together a new southern government.
The peace agreement is designed to end two decades of war between the Muslim north and the mainly Christian south of the country that left an estimated 1.5 million people dead.
As part of the deal, Mr Garang will become vice-president in the central government and will lead an autonomous government in the south from Rumbek.
The BBC's Jonah Fisher, in Rumbek, says Mr Garang faces enormous challenges transforming his movement into one capable of developing one of the most poverty-stricken and war-ravaged countries in the world.
Rumbek itself has no paved roads or multi-storey buildings and hardly any running water or electricity.
'Honourable and dignified'
Mr Garang was received at the airport by a delegation including the United Nations chief envoy to Sudan, Jan Pronk, and greeted by a marching band, traditional dancers and a large crowd of onlookers.
As he got off the plane, Mr Garang stepped over a white cow that had been slaughtered on the tarmac. A white cow is considered a peace offering among Mr Garang's Dinka tribe.
"It feels great after a peace agreement - honourable and dignified - you can see the people are very happy," Mr Garang told the BBC.
"Our first task is to ratify the agreement. That's why we have come to Rumbek... The same thing will be done in Khartoum."
Mr Garang has said the first priority for the planned SPLM administration in the south will be the voluntary repatriation of refugees and the provision of basic humanitarian needs.
Under the terms of the peace deal, the government of southern Sudan will share oil revenue equally with the government in the north. Hundreds of millions and perhaps even billions of dollars will flow to Mr Garang's new administration.
The Dutch Development Minister, Agnes van Ardenne, visited Rumbek on Friday, promising $130m in European aid - but made it conditional on an end to the continuing conflict in the western region of Darfur.
The UN is hoping to deploy in March some 10,000 international peacekeepers to monitor the agreement, between the Islamic government in the north and Christian and Animist rebels.
But UN sources say the deployment could be delayed by a dispute over which countries will provide the troops.
The SPLM is reported to believe that too many Muslim countries have been asked to contribute.