Wen Jiabao also met Prime Minister Gordon Brown during the visit
A number of protesters from the Free Tibet group were handcuffed by police after trying to approach Chinese Premier Wen Jiabao during his UK visit.
Several people vaulted barriers as he arrived outside the Chinese Embassy in London amid a noisy demonstration.
Supporters of Mr Wen were also outside the building, where he was greeted by dragon dancers and firecrackers.
The Chinese Prime Minister had earlier met Tory leader David Cameron and shadow foreign secretary William Hague.
The focus of the meeting had been on the global financial downturn, with the UK and China both keen to boost their economic ties.
But Mr Hague had said the talks would not gloss over China's human rights record, adding: "We always in our meetings with Chinese leaders raise issues of human rights and Tibet."
Slogans and placards
After the meeting, Mr Wen travelled to the Chinese Embassy where a group of around 100 were chanting pro-Tibetan slogans and brandishing placards from behind barriers.
BBC correspondent Barnie Choudhury said Mr Wen took no notice of the protest as he made his way into the building.
"Protesters vaulted over the barriers and made their way across the road," he said.
"Police decided they had to go in and began trying to hold the protesters back as they try to breach the barriers."
Officers were filmed taking at least two men away in handcuffs.
Mr Wen's European tour, which includes three days in Britain, takes in Germany and Spain.
He will also visit the EU headquarters in Brussels and the World Economic Forum in Davos.
The Chinese PM is expected to join celebrations in London on Sunday afternoon to mark the start of the Chinese New Year.
He will also make a speech at the University of Cambridge, the Chinese Foreign Ministry said.
'Troubled times'
BBC News correspondent Jill McGivering said Mr Wen is expected to promote China's economic prospects and push for more investment from the UK.
She said: "These are troubled times - and Britain and China are sticking together.
"Gordon Brown sees China as a powerful ally as he presses for reform of international financial bodies.
"And China's economy - expected to grow at about 7% this year - is very attractive to British investors."
She added that Mr Wen would be seeking reassurance that the UK will join China's fight against global protectionism.
This is when governments restrict import quotas in a bid to protect domestic industries from global competition - but China says this is damaging to its export trade.
The visit follows an announcement earlier this month by Foreign Secretary David Miliband that improving relations with China is to be a "major priority" for the UK in the years ahead.
'Candid'
In a 20-page framework document Mr Miliband said the UK will be "candid" when it disagrees with China, but will build a relationship based on co-operation
He also stressed the importance of economic ties between the two countries and emphasised China's growing role in international affairs.
The document represents a sort of stock-taking of ties between London and Beijing and sets out aspirations for the way in which Sino-UK ties should develop over the next four years.
Mr Wen has snubbed France during his European tour, reportedly because of a meeting between President Nicolas Sarkozy and the Dalai Lama late last year.
China reacted at the time by cancelling a scheduled summit with the EU.