There was tight security as members of the two houses met in their new facility in the country's new capital, Naypyitaw, the Financial Times reported. The members were to elect speakers of both the houses before choosing a president and vice presidents, the report said.
The opening session put into effect a new constitution but 25 percent of the Parliament seats would be reserved for the armed forces, which critics say will ensure real power still rests with the generals who have ruled Myanmar, formerly called Burma, since 1962, the BBC reported.
"The military is staying in control but some of them are taking off their uniforms," Win Min, a professor at Payap University in Thailand, said in a report in The New York Times.
The military-supported Union Solidarity and Development Party was declared winner of 77 percent of the votes in the November elections, which were boycotted by the party led by pro-democracy leader and Nobel Peace Prize winner Aung San Suu Kyi.
The country's courts have refused an appeal by Suu Kyi to have her National League for Democracy party reinstated.
Suu Kyi spent most of the past two decades under house arrest. She was released after the elections.
In a message on her party's new Web site, www.nldburma.org, Suu Kyi said the site was needed for the party to set up a people's network for democracy that will span the whole world.