The two kits will become phenomenal dam builders.
Beavers have been born in Essex for the first time since the Middle Ages - and public vote is being held to pick names for the beaver babies.
The mammals had been hunted to extinction for their meat, fur and scent glands in the UK by the beginning of the 16th century but have since been reintroduced.
A pair of Eurasian beavers were brought to the Spains Hall Estate in Finchingfield last year as part of a project to help reduce flood risk.
They were the first to be brought to Essex in 400 years, and now they have had two babies - known as kits.
Darren Tansley, river catchment coordinator at Essex Wildlife Trust, said: "We always hoped that having beavers present would benefit the wildlife on site, but the changes we have mapped over the past 18 months have exceeded our expectations.
"DNA samples from the main beaver pond recorded everything from deer to tiny pygmy shrews and all this to create the perfect environment for their young kits, the first beavers born in Essex since the Middle Ages.
"We are thrilled by the addition of two more ecosystem engineers in the county."
The adult beaver pair, Woody and Willow, have been building dams since their arrival as part of a partnership project with the Environment Agency and others.
Spains Hall Estate manager Archie Ruggles-Brise described news of the beaver babies as "fantastic".
"If they are anything like their parents, the two kits will become phenomenal dam builders, and we will be watching closely as they expand the wetland and provide even more protection against flood and drought, and provide homes for loads of other wildlife," he said.
Sam Russell is a reporter with PA.