The suspect has been identified as Chris Dumas.
The incident began before 11 p.m. Saturday in Magnolia.
Police say a woman stopped at a liquor store on the White Horse Pike and left the engine of her SUV running while she went inside.
A boy and girl, ages 8 and 10 respectively, from Lawnside were in the back seat.
Police say Dumas got into the SUV and sped away on the White Horse Pike.
Dumas turned on to Merchant Street and collided with another SUV at Hampshire Street.
The impact sent the stolen SUV up onto a curb. It rolled onto its roof.
Dumas and both children were taken to Cooper University Hospital, all with injuries said to be minor.
Police said Dumas has been released from the hospital and is now at Camden County Jail.
He is being charged with two counts of kidnapping, two counts of child endangerment and theft.
So far, no charges have been field on the mother.