Mr Su was a vice-chairman of China's parliamentary advisory body.
The Central Commission for Discipline Inspection (CCDI) said he had used his position to obtain "large bribes".
State media had announced in June 2014 that the government was investigating him for corruption.
The CCDI statement (in Chinese) said that Mr Su had been expelled from the party and relieved of all positions.
It added that his behaviour had "resulted in serious violations of the law" and that "the issue of his alleged crime, clues, and evidence have been handed to the legal authorities for them to take action".
It said that Mr Su had abused his position of authority, receiving "large sums of illegal bribes" which resulted in "huge losses of government assets". The statement did not give figures.
Mr Su, who was previously the top Communist Party official in Jiangxi province, was also found to be "chiefly responsible for the serious corruption problem that has emerged in Jiangxi".
Chinese media reported in November last year that several officials from a city in Jiangxi said to have links to Mr Su were arrested.
He was one of 23 vice-chairmen with the Chinese People's Political Consultative Conference, which was seen as a prestigious position. The conference advises China's legislature, the National People's Congress.
China has been conducting a widespread crackdown on corruption since President Xi Jinping took power in 2012, and has arrested dozens of officials and others in the private sector. The authorities have also gone after those who have fled the country, and extradited hundreds of suspected "economic criminals" back to China last year.
Mr Su is considered to be among the most senior government figures caught in the dragnet, along with former security chief Zhou Yongkang who was arrested in December.

Ms Dati gave a furious television interview denying any wrongdoing.
According to France's Le Point, the purchases included Hermes scarves.
The claims date to 2007-2010, during which time she was was justice minister under ex-President Nicolas Sarkozy.
Ms Dati, now an MEP for Mr Sarkozy's UMP party and mayor of Paris's 7th arrondissement, said it was normal practice to buy presents for foreign delegates.
A letter from the Cour des Comptes, which audits state accounts, lists €9,850 of unsuccessful claims - including hundreds of euros for pastries, as well as almost €1,500 on luxury gifts and more than €1,600 on clothes and accessories.
Another €180,000 spent on communications strategy was also rejected.
Ms Dati said the auditors had ruled against the justice ministry administration and not against her.
The auditors rejected the claims due to a lack of supporting documents and justification.
"The ministry of justice has never financed my personal costs or bought me any item of clothing," Ms Dati told AFP earlier this week.
"The state auditor has never accused me of anything, either personally or professionally."
Speaking to the French TV channel iTele on Thursday, she attacked media coverage of the auditors' decision and said there was a political plot against her.
She said she had suffered racist attacks - being dismissed as an "Arab" - as well as sexism within her party, and that she had complained to Mr Sarkozy.
Ms Dati was the first Muslim woman to serve as a government minister in France. She has long complained of sexism and elitism in French politics.
She resigned as justice minister in 2009 amid criticism of her management style and gossip about her clothes and love life.
Correspondents say the UMP is keen to move on from a series of financial scandals, including an ongoing investigation into party funding, ahead of Mr Sarkozy's expected bid for the presidency in 2017.
Former senior official Su Rong has been expelled from the Chinese Communist Party for corruption and faces prosecution, said the country's top anti-corruption body.
[NEXT_CONCEPT]
France's former Justice Minister Rachida Dati has hit out at "political plotters" in her own UMP party after it emerged auditors had rejected expenses claims of nearly €190,000 (£137,000) for items including luxury clothing.