The trial of Lee Ming-che was also China's first known criminal prosecution of a non-profit group worker since Beijing passed a law past year tightening controls over foreign nongovernmental organizations.
Kao urged the Taiwan government to make representation to China about the verdict against Lee because anything he did in Taiwan, whether circulating articles or posting comments online, were fundamental rights guaranteed by the Constitution of the Republic of China and beliefs deeply held by Taiwanese people.
A Chinese co-defendant named Peng Yuhua was sentenced to seven years in prison. Both men said they would not appeal.
President Xi Jinping, who consolidated power at a Communist Party congress last month, has cracked down on dissent and tightened control on civil society since taking office in 2012.
"Fighting for human rights for the disadvantaged is a commitment that must be made to push for the enhancement of human civilisation..."
"I think my husband now needs to figure out how to face up to his current situation", she said.
"Lee Ming-cheh has committed no crime and should be immediately and unconditionally released".
"Lee Ming-che should not have to spend a day in jail, since everything he did peacefully discuss current events and historical issues on social media is expressly protected under global law", Nee told AFP news agency.
Lee Ming-cheh sentencing
The verdict "indicates China's indifference to the universal values of democracy and human rights, and damages its worldwide reputation, while hurting the feeling of Taiwanese", the DPP said.
Teng Biao, a Chinese lawyer who once taught at the University of Politics and Law in Beijing, told CNA from New Jersey in a telephone interview that even if Lee is given a light sentence, it would not mean China is showing goodwill to Taiwan or adjusting its policy toward Taiwan. "We regret that Lee's case seriously damaged cross-strait relations", the presidential office said in a statement. China views Taiwan as part of its territory waiting to be reunified.
Former DPP lawmaker Wang Li-ping tried to go to the court with Lee's wife, but Wang was expelled from mainland China upon arrival at Changsha airport.
The European Parliament passed a resolution in July calling upon China to release Lee.
Yibee Huang, the chief executive of Covenants Watch, an alliance of human rights organizations in Taiwan, described a "chilling effect" on Facebook use by friends and associates since Mr.
In the lead-up to the trial, Beijing repeatedly ignored Taipei's requests for information on Lee's whereabouts and details of the allegations against him.
International rights groups, including Amnesty International, have called on world governments to continue to exert pressure on China authorities to address the plight Lee and many other Chinese rights defenders face.
Taiwan began its transition to democracy following the death of President Chiang Ching-kuo, in January 1988, starting with direct elections to the legislature in the early 1990s and culminating in the first direct election of the island's president, Lee Teng-hui, in 1996.