Xi and Rousseff whose nations marked 40 years of diplomatic relations, also launched the Portugueselanguage version of China's Baidu internet search engine.
"Our relations, which represent a truly strategic partnership, are detveloping at an unprecedented speed in diverse areas of cooperartion," Rousseff said
Xi said China aims to "strengthen our strategy to create an even more prosperous future for our nations."
After Brazil, Xi is heading to Argentina, a key source of soybeans for China, before visiting oil-supplier Venezuela and communist ally cuba