According to the video, the terrorist Free Syrian Army is forcing children as young as 12 to join their ranks to carry out attacks.
The footage also shows children being forced to dig their own graves before joining militants.
Children have been the main victims of the past months of unrest in Syria that began in March 2011.
There are many instances where the militants massacred children during raids on civilian areas.
Recently, a disturbing video on the Internet showed militants having a child behead a captive.
Human Rights Watch has interviewed several teenagers who said they had worked with the militants in a number of cities in Syria.
The Syrian government says that the chaos in the country is being orchestrated from outside, and that certain Western states and their regional allies are trying to fuel the turmoil.