Before traveling to the People's Republic on Friday for a two day visit, the new American Secretary of State, said she would not let the issue "interfere" with efforts to resolve the global economic crisis and combating climate change.
Human rights groups claimed her comments lifted the pressure on Beijing to address the issue, making it easier for the Chinese to justify fresh restrictions on dissidents.
"I am under house arrest because Hilary Clinton came," said Zeng Jinyan, the wife of China's most prominent activist Hu Jia, via an email message.
Mrs Zeng said she had been told by the police who monitor her that she and her baby daughter would not be allowed outside. Her husband is serving a three-and-half-year prison sentence.
Mrs Clinton's failure to press Beijing on human rights appears to contradict the desire of President Obama to restore America's reputation, after the Bush administration was criticized for flouting international law by torturing terrorist suspects and detaining them indefinitely.
Last month, President Obama was hailed for his decision to close the controversial Guantanamo Bay detention facility in Cuba, where some prisoners have been held without trial for more than seven years.
The Chinese Human Rights Defenders, a group comprising some of China's most determined activists, said the authorities had told dissidents that they would not be allowed to move freely during Mrs Clinton's visit.
They were either placed under increased surveillance or locked in their homes and barred from receiving visitors.
Some activists were reported to have been detained by police at guesthouses outside Beijing.
Many of those who have been targeted by the Chinese authorities signed the Charter 08 petition in December. The petition, which was issued on the 60th anniversary of the Universal Declaration of Human Rights, called for political reform, freedom of expression and democracy in China.
It was signed by 303 intellectuals and activists, including Yu Jie, a blacklisted writer who was visited by plainclothes police on Friday.
"They said I was to receive heightened monitoring throughout Clinton's visit, but it would end once she left," said Mr Yu.
Although China always steps up the harassment of dissidents during visits by foreign leaders, 2009 is also a particularly sensitive year for Beijing.
The 50th anniversary of the failed uprising in Tibet, which resulted in the Dalai Lama fleeing into exile, falls in March, while June 4 marks the 20th anniversary of the crushing of the Tiananmen Square pro-democracy protests.
It also represents a dramatic volte-face by Mrs Clinton.
Last year she called for then President Bush to boycott the opening ceremony of the Beijing Olympics as a protest against China's crackdown in Tibet last March and its failure to do more to end the genocide in the Darfur region of Sudan.
In 1995, while in Beijing for a UN conference, Mrs Clinton described China's one-child policy as a "violation of human rights".