Bo Xilai, who has been jailed since March 2012, was indicted in July on charges of corruption, abuse of power and accepting bribes.
Journalists were not inside the courtroom and have had to rely on microblog posts by the court for details of the proceedings, The New York Times reported.
One post said Bo had denied taking $180,000 in bribes from businessman Tang Xiaolin. Prosecutors said another businessman, Xu Ming, gave Bo another $3.4 million in bribes.
A separate posting said Bo had denied bribery in that instance as well.
Until his arrest last year, Bo, 64, was one of 25 members of the Politburo and considered a candidate for one of the highest posts in the Chinese Communist Party.