On Thursday, the president ordered the release of 452 prisoners, and on Sunday another 66 prisoners were granted amnesty, said Xinhua.
The 31 foreign prisoners were extradited soon after they were freed.
The amnesty is seen as part of the government's continued democratic reform. It comes just ahead of US President Barack Obama's historic visit to Myanmar scheduled for Monday.
Since the new government assumed office in March last year, 514 prisoners have been freed in sixth amnesties till September this year.
Sunday's amnesty brought the total number of prisoners pardoned to 29,536 since the new government was installed.