Hu Jintao, the Chinese president, said aid would double by 2009 but stopped short of disclosing the value. China will also provide three billion dollars of preferential loans and two billion dollars of preferential buyer's credits loan to the continent, he said.
Beijing would also cancel more debt owed by poor African countries in the form of interest-free government loans, he announced.
Business is a major focus of the summit, with more than 2,500 deals being discussed during the three-day summit at the Great Hall of the People on Tiananmen Square.
China is seeking to improve its ties with Africa, whose mineral and oil wealth it covets and whose countries form an important strategic bloc vote in world bodies.
"Our meeting today will make history," he said in a speech to African leaders at the beginning of the summit.
The volume of African exports to Asia has increased by 20 per cent in the past five years, largely due to resource-hungry China buying up raw materials.
Ghana recently clinched a $3 billion iron ore deal with a Chinese consortium and is finalising a $600 million hydro-electric project backed by Beijing.
"China will forever be a good friend, good partner, good brother of Africa."
Hu Jintao, Chinese president at the opening of the Beijing Summit of the Forum on China-Africa Cooperation
Last week, China announced plans to ship home copper once a $200 million smelter with a maximum capacity to produce 150,000 tonnes of finished copper is built in Zambia.
Hu said China would further open up its market to Africa by increasing the number of tariff-free export products and establish three to five trade and economic cooperation zones.
A five-billion-dollar development fund to encourage Chinese companies to invest in the continent will also be set up.
"China will forever be a good friend, good partner, good brother of Africa," Hu said.
But rights groups have expressed concerns about links to countries like Zimbabwe and Sudan.
New York-based Human Rights Watch said China is helping to support authoritarian governments.
"China's policies have not only propped up some of the continent's worst human rights abusers but also weakened the leverage of others trying to promote greater respect for human rights," it said in a statement.
The group suggested that China use its growing influence in the continent to promote human rights instead of "bolstering governments in places like Sudan and Zimbabwe".