The billionaire tycoon, who lost his parliamentary immunity when he was ejected from the Senate last year over a tax fraud conviction, is not expected at the hearing and is not obliged to attend under Italian law.
The 77-year-old is accused of giving €3 million in 2006 to Sergio De Gregorio, then a senator from the anti-corruption Italy of Values party, to join his People of Freedom (PdL) party and help undermine the centre-left government in power at the time.
A former Berlusconi aide, Valter Lavitola, is also on trial for being the alleged intermediary for the bribe.
The trial is in Naples as it was the seat occupied by De Gregorio, who is collaborating with investigators.
The two first hearings in the trial on Tuesday and Wednesday are expected to be largely procedural.
Among the issues on the table will be a request from Senate speaker Pietro Grasso to be considered a plaintiff in the trial - a move that has proved hugely controversial among Berlusconi's supporters.
A new judge is also due to be named as the current one has declared a conflict of interests - she is married to a prosecutor who worked in another trial in which Berlusconi was convicted for having sex with an underage 17-year-old prostitute and abuse of office.
The list of witnesses for the trial includes former prime minister and former European Commission president Romano Prodi, as well as two former senators expected to say they were offered bribe money by Berlusconi.
De Gregorio has told investigators that he received €2 million in cash and €1 million for his political movement "Italians in the World".
Berlusconi's lawyers Michele Cerabona and Niccolo Ghedini are expected to argue that corrupting the senator would have been impossible since every lawmaker can vote freely, whatever their party affiliation.
Berlusconi this year will also be appealing his prostitution and abuse of power convictions, as well as one for leaking a confidential police wiretap in an attempt to damage a centre-left political rival.
The three-time former prime minister was forced out of parliament for the first time in his 20-year political career in November following a tax fraud conviction.
While Berlusconi does not have to go to prison because of his age, a court in April will decide whether he has to do a year of community service or house arrest for that crime and he has lost his parliamentary immunity.
The ban from parliament has not prevented Berlusconi from seeking to remain a powerful force, however.
While some of his former proteges have switched to the New Centre-Right (NDC) party in a ruling coalition with Prime Minister Enrico Letta, Berlusconi is rallying support for his re-founded (Go Italy (Forza Italia) party.
He is unrepentant despite his frequent run-ins with the justice system, dismissing charges against him as politically motivated, and he still enjoys the support of six or seven million Italians according to polls.
Berlusconi has vowed a robust campaign ahead of the European elections in May and on Saturday he declared that the euro was "a foreign currency" for Italians.
In a phone-call to supporters this weekend, he got confused about where he was calling and joked that it must be the fault of "some left-wing secretary".
But after 20 years of "Berlusconism" and a two-year economic crisis, there are indications that the attention in Italy is shifting away from Berlusconi.
The main political interest now is on the centre-left - the rivalry between Letta and the ambitious new head of the Democratic Party, 39-year-old Matteo Renzi.