The verdict on Ching Cheong, who worked for Singapore's Straits Times newspaper, was handed down by the Beijing No 2 Intermediate People's Court on Thursday, Xinhua news agency reported.
Ching, 56, was put on trial behind closed doors two weeks ago after being detained for 16 months on charges of spying for Taiwan in a case that rights groups have called a warning for Chinese and foreign journalists in Beijing.
"He has been given five years. I'm sorry, but I cannot give any further details," lawyer He Peihua said in an interview seen on Cable TV News in Hong Kong.
The court also ordered the confiscation of 300,000 yuan ($37,500) worth of property belonging to Ching, essentially a fine on top of the jail term.
Fellow journalists expressed anger at the sentence and warned it would have a "chilling effect" on coverage of China.
Ching had been treated unfairly and shamefully, they said.
"His sentence was not fair - it's not acceptable that a closed court can sentence someone for so long," said Hong Kong Journalists' Association vice chairman Lo King-wah.
China espionage cases
August 1998: A Chinese court jailed Taiwan businessman Kou Chien-ming for four years.
April 1999: Yeh Ping-nan, a former colonel in Taiwan's military Intelligence Bureau and the island's former spy master in Hong Kong, was taken into custody in the southern Chinese city of Guangzhou. It was unclear if Yeh was ever sentenced but he returned to Taiwan in May 2003.
August 1999: Chinese Major-General Liu Liankun and Senior Colonel Shao Zhengzhong were executed by lethal injection for selling state secrets to Taiwan for $1.6 million in the biggest spying scandal of China's Communist era.
December 2003: Chinese state media announced the arrest of 24 spies from Taiwan and 19 Chinese accomplices. It was unclear if they were ever jailed.
October 2004: A Chinese court jailed Wei Pingyuan, a Hong Kong resident with British citizenship, for life and ordered the seizure of all his assets for spying for Britain. Co-defendant Cai Xiaohong, former secretary-general of the Liaison Office of the Central Government in Hong Kong, was jailed for 15 years for providing state secrets to foreigners.
April 2006: Tong Daning, a national pension fund executive, was executed for spying for Taiwan.
June 2006: Chen Hui, an official at the Chinese Academy of Social Sciences, was jailed for 13 years in prison for selling state secrets to Japan, a government source said.
James Lung, co-ordinator of the Hong Kong-based Rescue Ching Cheong Alliance, said in reaction to the long-awaited verdict: "Five years is not a short amount of time. We think it's very unfair, because from the beginning to the end nobody knew what happened."
He told AFP that Ching's wife, Mary Lau, favoured an appeal but that she was discussing it with other members of the family.
"She believes the sentence is very unfair and that she cannot accept the decision," said Lung.
"She is in talks with Ching's family about appealing. She wants to appeal but her family are concerned that if she does, Ching may get a stiffer penalty. They think five years would be better than 10."
Lung said the sentence was shameful to all Chinese and he regarded the fine as "robbery".
"This is all the money that he can rally - it's robbery that he has to pay this," said Lung.
Ching's employer, Singapore Press Holdings, issued a statement expressing concern.
"As he is known to be suffering from high blood pressure and is not in the best of health, we appeal to the Chinese authorities to show him leniency and compassion," it said.
"We wish to reiterate that since his recruitment in 1996, he has served us with distinction and has never given us cause to question his integrity and professionalism.
"We are in touch with his family and will provide all necessary support and assistance."
His wife Lau has always maintained his innocence, saying Ching apparently fell into a trap set over sensitive materials on late Communist Party chief Zhao Ziyang, who was sacked for opposing the 1989 Tiananmen crackdown.
She also said Ching had helped an academic at a Chinese government think-tank compile reports on Hong Kong and Taiwan commissioned by the central authorities, and gave advice on cross-strait relations.
The problem was he may have given too much information on mainland China to Taiwan authorities, according to Hong Kong media. The charges also seem to suggest this.
The verdict also deprived Ching of his political rights for one year, Xinhua said.