Li said the sides would seek to strengthen cooperation between their traditional and new media and Cameron said Britain would open a consulate in the central Chinese city of Wuhan, the country's fifth in mainland China
Separately, an agreement was announced to expand the British Premier League's program to train Chinese coaches and referees and to boost cooperation between it and China's top-flight Super League.
Cameron told Li the delegation was interested in building trade relations.
"We particularly want to explore all the opportunities of economic openness, openness of Britain to Chinese investment, which we've seen huge amounts of in recent months and years, but also the opportunities for further opening our trade relations," Cameron said.
Neither leader mentioned the Dalai Lama meeting in their statements after the signing ceremony, although Li said China appreciated Britain's respect for its "core interests and its major concerns."
Cameron said discussions should include "those issues where we have differences," and said Britain looked forward to holding a human rights dialogue with China early next year.
"We should approach these with mutual respect and understanding, as we did today," Cameron said.