The charity is campaigning to help protect ancient or old trees, that have grown in the UK for hundreds of years.
They say that having more trees is good for our health as well as the environment.
Currently around 2% of the UK is listed as ancient woodland.
The UK has seen around 45 rare species of trees disappear in the last 100 years.
Some people are calling for lots more homes to be built in the UK and the Woodland Trust say they are worried that building new houses would mean that old trees would be chopped down to clear space.
The Government have been talking about the issue in a new White Paper, which presents ideas for changes to the law.
It could mean that some trees in England would be protected like historic buildings.
The Woodland Trust have said that some trees should have the same rights as old buildings.