Thousands of Tongans have lined the route from the palace to the royal tomb in preparation for the passage of the casket carrying the late King George Tupou V.
The road to the tomb in the capital Nuku'alofa is packed with people waiting to farewell the monarch who reigned over them for six years.
Inside the burial ground, seated students line the edges of the giant tapa - a woven and printed mulberry bark mat which is Tonga's equivalent of the red carpet.
It leads to the burial chamber where the King will be interred.
Officials say the monarch will be carried to his resting place on an ornamental platform held aloft by 150 people.
Australia's Governor-General Quentin Bryce will be among the foreign dignitaries attending the funeral.
The country is swathed in black during the official mourning period, which lasts until mid-June.
The king, a colourful and sometimes controversial ruler, died in hospital in Hong Kong eight days ago.
He had been treated for cancer and type-2 diabetes.
His body was returned to Tonga yesterday, and an all-night prayer vigil was held overnight.
During his reign, which began in 2006, he relinquished many of the monarchy’s powers and was a driving force behind the country's first democratic elections.
He was known for his penchant for elaborate uniforms and was driven around his country in a London taxi cab.