Groups like Amnesty International and the UN are working to end the use of child soldiers in wars.
The UN is campaigning to tighten up laws on selling guns to stop them reaching battlefields where child soldiers are fighting.
The UN Convention on the Rights of the Child says that "all children have the right to special protection in time of conflict and should not take a direct part in hostilities."
There are lots of projects now being set up across the world to help ex-child soldiers. They give the kids an education and counselling to try and help them return to civilian life.