Jailed Chinese dissident Liu Xiaobo won the 2010 Nobel Peace Prize and the award was immediately condemned by China as honouring "a criminal".
The award, by the Norwegian Nobel Committee, was for Liu's use of non-violence to demand fundamental human rights in his homeland.
Chinese state media immediately blacked out the news, Chinese government censors blocked Nobel prize reports from internet websites and China later summoned Oslo's ambassador to Beijing to make a formal protest.
In Oslo, China's ambassador to Norway met with a state secretary at Norway's Foreign Ministry, Norwegian Foreign Ministry spokeswoman Ragnhild Imerslund said. China requested both meetings to express its discontent with the peace prize decision, Ms Imerslund said.
She said the Norwegian officials explained that the peace prize committee was independent of the government and that Norway wanted to maintain good relations with China.
This year's peace prize followed a long tradition of honouring dissidents around the world, although it was the first Nobel for China's dissident community since it resurfaced after the country's communist leadership launched economic but not political reforms three decades ago.
Liu, 54, was sentenced last year to 11 years in prison for subversion. Unlike some in China's persecuted dissident community, he has been an ardent advocate for peaceful, gradual political change rather than confrontation with the government.
The Nobel committee praised Liu's pacifist approach and cited Liu's participation in the Tiananmen Square protests in Beijing in 1989 and the Charter 08 document he recently co-authored, which called for greater freedom in China and an end to the Communist Party's political dominance.
Chinese authorities would not allow access to Liu. In Beijing, his wife expressed her joy at the news. Surrounded by police at their Beijing apartment, Liu Xia was not allowed out to meet reporters. Instead she gave brief remarks by phone and text message, saying she was happy and that she planned to go on Saturday to deliver the news to Liu at the prison, 300 miles away.
US President Barack Obama urged China to release Liu Xiaobo quickly. Mr Obama called him an "eloquent and courageous" supporter of human rights and democracy.