The boy told officers his mother chained him in her bedroom as punishment and forced him to sleep on the floor with no covers, the South Jersey Times in Woodbury reported Tuesday.
He managed to break his chains Monday and run to a neighbor's house in Camden, police said.
His mother, Florence M. Pollard, called police Monday afternoon to report the child, identified only as M.P., had run away. A neighbor called police shortly afterward to report the boy was at a home a few blocks away.
Camden County police said they found a metal chain attached to a radiator in the mother's bedroom during a search of the family's home.
Pollard and her boyfriend, Brian L. Craig, 29, were arrested and charged with endangering the welfare of a child and criminal restraint. Both were jailed in lieu of $50,000 bond each.
The boy, his two sisters and three brothers ranging in age from 7 months to 11 years were taken into custody by the New Jersey Division of Child Protection and Permanency.