It happened around 8:40 p.m. Wednesday on the White Horse Pike in Egg Harbor City.
Police said a 2011 GMC pickup truck driven by 30-year-old Jorge Rodriguez was traveling west approaching Buffalo Avenue.
At the same time, the boy, his grandmother and brother were crossing the White Horse Pike.
The 7-year-old boy and his grandmother were struck by Rodriguez's truck, the Egg Harbor City Police Department said. The younger brother was not injured.
The 7-year-old was identified by his family as Marco Yu. He was pronounced dead at the scene, his grandmother was transported with life-threatening injuries.
Marco's father said they were getting groceries prior to the deadly accident.
Rodriguez was charged with being an unlicensed driver involved in a fatal motor vehicle crash.
Rodriguez was also issued a motor vehicle summons for being an unlicensed driver. He was processed and released on a complaint-summons.
Anyone who witnessed the crash should call the Egg City Police Department at (609) 965-2901 or the Atlantic County Prosecutor's Office Crash Investigations Unit at (609) 909-7800.