"And we are delighted the visitor centre is being built because it will help present this important site to the public in the way it should be for the first time.
The 1,500-year-old burial plots were found at Sutton Hoo, in Suffolk, where a 24m (80ft) long, wooden ship and treasure were discovered in 1939.
The investigative dig was being done ahead of construction work for a new visitors' centre on the site, due to open in 2002.
Archaeologists found artefacts and remains that indicated at least 18 cremations and five burials dating from the 6th or early 7th centuries.
The discovery included a rare type of ornamental bronze bowl, called a hanging bowl, which accompanied one of the cremations.
The Suffolk County Council Archaeological Field Project Team said the male bodies were buried with spears and shields, and the females with ring brooches and beads.
What remains of these items has been removed from the site for safe keeping and further investigation.
Medieval Britain
The exact location of the cemetery is about 500m from the boat find of 61 years ago, on the bank of the River Deben near Woodbridge.
"We're thrilled that these discoveries will add to the knowledge we have about Sutton Hoo," said Dr Rosemary Hoppitt, chairman of the Sutton Hoo Society.
"And we are delighted the visitor centre is being built because it will help present this important site to the public in the way it should be for the first time.
"If the development had not been going ahead we would never have found these new items."
The treasures uncovered in 1939 are now on display in the British Museum. The hoard of gold and silver items - believed to be the treasure of one of the earliest English kings, Radwald, King of East Anglia - included a ceremonial helmet that has become one of the defining images of early Medieval Britain.
The find forced a rethink of the period known as the Dark Ages and showed people living at that time had previously unimagined sophistication and culture, as well as a structured society.