A Central Otago woman faces a prison sentence after beating her son with a soup ladle.

The Ranfurly woman was remanded in custody after pleading guilty in Alexandra District Court yesterday to assaulting the seven-year-old.

She had become angry with her son when he struggled with his homework and took to him with the 30cm ladle and her hands, The Southland Times reported.

The April 28 attack left the boy with extensive internal and external bruising and he has since been moved into the care of Child Youth and Family.

The woman's lawyer applied to have her released on bail to care for her remaining children but that was rejected by Judge Dominic Flatley.

"Not enough is done about this sort of thing and this is an appalling assault on this poor boy," he said.

"Imprisonment is inevitable."

The woman was remanded in custody until July 29.