"China will undertake greater international responsibilities," Wen said in a joint media appearance with Barroso after their talks.
"This is not only to meet international expectations but also serves China's interests."
"The European community and China's strategic partnership is even more relevant in an increasingly globalised world," Barroso said.
"Whether it is in leading a global economic recovery, resisting protectionist pressures, defending against the threat of climate change or addressing nuclear proliferation and other security questions, China and the European Union need to work together," he said.
On the Iranian nuclear issue -- a key concern of the EU and United States -- Wen did not say whether Beijing would support new sanctions on Tehran.
He said only that China was committed to the global nuclear non-proliferation regime and upholding peace in the Middle East.
"China will remain in touch with the relevant parties and will play a positive and constructive role for the early and proper settlement of the Iranian nuclear issue," Wen said.
The United States, Europe and others fear Tehran seeks to build nuclear weapons. Iran insists its atomic programme is purely for civilian energy use.
Western nations are calling for a fresh round of UN sanctions but Beijing -- a veto-wielding permanent member of the UN Security Council -- has so far resisted such a move.
"China and the European Union have far more consensus than differences," Wen said.
"We both stand for world multi-polarity and diversity (and) we both believe that major decisions in world affairs should be taken in an open, democratic and transparent manner."
The two sides also agreed to set up a climate change hotline between top environmental officials of the EU and China to help both sides coordinate their positions in global greenhouse gas negotiations, Barroso said.
Barroso and his delegation will leave Beijing on Friday to attend the opening of the World Expo in Shanghai.