Samoa is celebrating 48 years of independence after separating from New Zealand in 1962.
Samoa was previously under the colonial rule of Germany and Britain.
The celebrations are being attended by the King of Tonga, the Governor of American Samoa, the Ulu of Tokelau and many other invited guests and members of the diplomatic corps.
Radio New Zealand International reports the programme will start with the raising of the flag at Tiafau malae at Mulinuu.
That will be followed by a march-pass by schools and organisations, government ministries and corporations after a royal address or malelega by the Head of State, Tui Atua Tupua Tamasese Efi.
The village of Vailoa in American Samoa is providing entertainment.