The leaders discussed free markets and global financial reform
Prime Minister Gordon Brown has called for greater collaboration on trade between the UK and China.
Speaking after Downing Street talks with Chinese counterpart Wen Jiabao, Mr Brown said they shared a determination to reverse the economic downturn.
Mr Wen said "concerted efforts" were needed to "address the common challenges that we face".
Later, a protester threw a shoe at Mr Wen while he was giving a speech at Cambridge University.
Reuters reported that the shoe landed about a metre from Mr Wen.
It added that the protester, reported to be a young man, shouted "how can the university prostrate itself with this dictator?"
The BBC's Angus Crawford said the protester was taken away by police while AFP reported that fellow members of the audience shouted "shame on you" as he was escorted out of the auditorium.
The first two days of Mr Wen's three-day UK visit were met by protests over human rights abuses in China and Tibet.
Mr Wen told a Downing Street press conference that the economic crisis showed the "dangers of a totally unregulated market".
He added: "Only by working together, only by making a concerted effort, can we address the common challenges we face."
Mr Brown said: "My personal priority is securing and protecting the jobs of British workers in this country."
He added that he and Mr Wen shared a "determination that we can work together to solve the global economic problems".
Earlier, the two leaders addressed the Institute of Directors in London.
Mr Wen said: "Confidence is very important. With confidence business people are able to invest.
"With confidence, people are able to spend and with confidence we have the source of strength and power to tide us over the difficulties and meet the challenges that we are faced with.
"Pessimism and complaints will get us nowhere."
Mr Brown said the 4 trillion yuan (£400bn) fiscal stimulus announced by the Beijing authorities in November would help British exports to China, particularly in low-carbon technologies.
He added: "I look forward to seeing further progress, with new contracts being signed and new opportunities emerging for our businesses, especially in key sectors where greater collaboration can increase two-way trade."
Mr Brown said: "I believe that there is much scope for trade and investment to expand between our two countries even in these most difficult of times for the global economy.
"The strength of the relationship between China and Britain will be a pivotal force in helping us through the downturn and a powerful driving force behind our future growth and prosperity.
"We know from previous downturns that a retreat to narrow, short-term protectionist policies would only serve to deepen the global recession and we must not and will not allow that to happen again."
Five people were arrested on Sunday after trying to approach Mr Wen, who was booed as he travelled around London.
However, he was also greeted by supporters as he toured Chinatown and attended a dinner at the Natural History Museum.
Mr Wen also met Conservative leader David Cameron for 45 minutes on Sunday to talk about topics including the economic crisis and fighting climate change.
Mr Cameron raised human rights issues with the Chinese leader and emphasised the importance of "greater participation" in Beijing's political process.
Mr Wen's European tour includes visits to Germany, Spain, and Brussels.