Venezuela and China have "common interests", President Hugo Chavez said
Venezuela and China have agreed to double their joint investment fund to $12bn (£8.3bn) and signed a raft of agreements to boost co-operation.
These include increasing oil exports from Venezuela, currently China's fourth biggest oil provider.
"It is part of a strategic alliance," Venezuelan President Hugo Chavez said, after meeting the visiting Chinese Vice President Xi Jinping.
China has invested $8bn and Venezuela $4bn in the fund.
Currently China imports some 330,000 barrels a day from Venezuela, a figure planned to rise to 1m a day by 2015, the Associated Press reports.
Under one of the agreements signed, an oil refinery is to be built in China to handle Venezuelan heavy crude from the Orinoco basin.
"Our co-operation is highly beneficial," Mr Xi told reporters.
Mr Chavez said the Venezuela-China alliance served "common interests" and that Venezuela was committed to being an oil supplier to China "for the next 500 years".
The Venezuelan government regards Beijing as a key partner in its strategy to diversity oil sales from the US market, correspondents say.
Mr Chavez said the $12bn fund would be invested in education, infrastructure and health programmes in Venezuela, as well as farming and mining.
Brazil is the next stop for Mr Xi, who has also visited Jamaica, Mexico, and Colombia on his regional tour.
Chinese Vice Premier Hui Liangyu is also touring Latin America and the Caribbean - a sign of the region's importance to Beijing.
China's export markets in Europe and North America have shrunk substantially in the global financial crisis, so Beijing is desperate to open up and maintain markets in Latin America.
Beijing published its first ever policy document on the region last November before President Hu Jintao visited Costa Rica, Cuba and Peru.