The court posted a picture of Mr Bo - the first image of him in 18 months
Bo Xilai, the disgraced Chinese politician once tipped for the highest levels of power, has gone on trial on charges of bribery, corruption and abuse of power.
The former Chongqing Communist Party leader is accused of accepting money from two businessman, the court said.
The abuse of power charge relates to his wife's role in the murder of a British businessman, it said.
Mr Bo's trial is China's most politically-charged in decades.
Two years ago the 64-year-old high-flier was seen as a candidate for promotion to the Politburo Standing Committee, China's seven-member top decision-making body.
But in February 2012, as China prepared for its once-in-a-decade leadership handover, questions emerged over the death of the British businessman, Neil Heywood.
Mr Bo's wife, Gu Kailai, has since been convicted of Mr Heywood's murder. Mr Bo faces multiple charges and is widely expected to be found guilty.
His downfall was seen as the biggest political shake-up to hit China's ruling elite in decades.
'Fairly and justly'
The trial - which started at 08:30 (00:30 GMT) - is taking place at the Intermediate People's Court in Jinan, which is in Shandong province. The court is providing an account of proceedings on its official microblog.
"I hope the judge will try this case fairly and justly according to the law of the country," Mr Bo reportedly said.
Five of Mr Bo's relatives are said to be in court, along with 19 journalists and 84 other people. Foreign journalists have not been allowed in.
According to the indictment posted by the court, Mr Bo is accused of receiving bribes totalling 21.8m yuan ($3.56m; £2.28m) from two Dalian-based businessmen.
The court microblog quoted Mr Bo as saying about one of the cases: "That Tang Xiaolin gave me three bribes - that did not happen. He asked me to help him sort out something, and these were all done according to procedure."
Mr Bo said he had admitted this "against his will" under questioning, adding: "What I meant was that I was willing to take the legal responsibility but I had no idea of all these details back then."
The abuse of power charge is connected to his wife's role in Mr Heywood's murder and his treatment of Wang Lijun, his now-jailed former police chief whose flight to the US consulate brought the case out into the open, it said.
Hearings would last two days, CCTV said in a tweet, with a verdict "likely in early September".
Security was tight at the court, with police blocking the gates and lining roads leading up to it.
Earlier this week, Mr Bo's son, Bo Guagua, issued a statement from the US saying he hoped his father would have the chance "to answer his critics and defend himself without constraints of any kind".
The verdict, he said, would carry no weight if his well-being had been "bartered for my father's acquiescence or my mother's further co-operation".
As party leader in Chongqing, Bo Xilai was seen as a powerful, populist and charismatic figure.
He was known for two high-profile campaigns: a large-scale crackdown on crime and a drive to promote China's old communist values. But analysts said his ambition earned him enemies and he was considered controversial by top party leaders.
In February 2012, around the time that China was preparing to promote a new generation of leaders, his police chief, Wang Lijun, fled to the US consulate in Chengdu amid an apparent fall-out with Mr Bo.
Shortly afterwards, Chinese authorities announced that they were reinvestigating the death of Mr Heywood, and both Mr Bo and his wife disappeared from public view.
Gu Kailai has since been jailed for the murder of Mr Heywood - a crime she carried out, state media say, because of differences over a business deal. Wang has also been jailed for his role in covering up events, among other charges.
Mr Bo is the last major player in connection with the case to face trial. Interest has been intense, with many Chinese microbloggers speaking out.
Most expressed scepticism about the proceedings, judging the trial merely a political show. Nevertheless a large number still believe Mr Bo has a case to answer when it comes to corruption and abuse of power.
Herkuang in Shanghai says: "This Bo Xilai trial thing is merely a procedural thing. Those [party] elders have already made up their minds on what to sentence him with... Just watch the end result."
But some of comments about Mr Bo and his alleged conduct were dripping with sarcasm. "What a clean official! Just one count of bribe taking in 30 years as a civil servant?" Li Zhiqiang, law lecturer at Lanzhou University, said.
Other internet users were more complimentary, however. One user, "Small Town Girl", said ahead of the trial: "Looking at him from a rational perspective, he made contributions to the people of Dalian and Chongqing."