Since 2004, it has been supplying China with uranium oxide for us in nuclear power plants.
Arriving in Pretoria, the South African capital, on Tuesday, Hu is scheduled to hold talks with Thabo Mbeki, the president, and sign a slew of trade agreements.
Ties between China and South Africa have expanded rapidly since diplomatic relations were established in 1998, four years after the end of the apartheid regime.
Apartheid South Africa had shunned diplomatic relations with China, allying instead with rival Taiwan, which China considers a renegade province.
Today China is South Africa's second-largest import trading partner and eighth-largest export partner.
The two countries have also closely co-operated in pushing the agenda of developing nations in forums such as the United Nations and the World Trade Organisation.
"China understands that she can only prosper on a sustainable basis if Africa prospers on a sustainable basis"
South African president
South Africa has backed China in the face of growing criticism that it is only interested in exploiting Africa's vast mineral and oil riches while dumping cheap and often sub-standard goods there.
Mbeki had warned last year that Africa needed to guard against allowing ties with China to develop into a "colonial relationship".
But more recently he has warmed to China, expressing confidence that growing ties would not replicate historic colonial relations where Africa served as "a source of raw materials and a market for goods manufactured in the countries of the colonisers".
"China understands that she can only prosper on a sustainable basis if Africa prospers on a sustainable basis," he said.
On Monday, Wei Jianguo, China's deputy trade minister, rejected claims that his country was exploiting Africa.
"The label of neocolonialism cannot be stuck on China," the official Xinhua news agency quoted him as saying.
Wei said that the partnership between China and Africa rested on "equality, mutual benefit and economic cooperation in which both sides were winners".
From South Africa, Hu travels to Mozambique and the Seychelles on the final stages of his tour.