Maddy hears 11-year-old Christian's story
Thousands of children across the UK live in foster care because there are problems at their homes.
But there aren't enough places for all the children who need to be fostered, and the problem is worst for children older than eight.
Newsround spoke to Christian, 11, to find out what it's like being fostered.
He said: "I was really scared at first and thinking there is no way I want to live here, but then I realised it's not bad, they are really loving."
Christian can't live with his real parents - his mum died when he was very young and his dad lives in another country.
What is fostering?
It's when children get looked after by another family for a while or in a children's home
It could be a few days, months or sometimes years
It happens for all sorts of reasons - including because their own relatives are ill or they're having some problems
Christian is 11 now and has been living with foster parents Sylvia and Alan for the past six years.
That really helped Christian get through a difficult time, but not all children are that fortunate.
The problem is that not enough people are prepared to be foster parents for a long time like Sylvia and Alan.
That means a lot of children who are in care end up being moved all around the country to live with families for a short time.