Republican representative Chris Corley has been charged with first degree domestic violence and pointing a firearm at a person.
The call was made on Monday evening, and released by police to local media.
Mr Corley, 36, recently voted for legislation toughening punishments for domestic violence.
"Just stop Daddy. Just stop...Daddy, why are you doing this?''  can be heard in a recording released to the Aiken Standard newspaper.
In a second call, a woman identified by the Aiken County Sheriff's Office as Mr Corley's mother-in-law tells a dispatcher: "He beat his wife and he's threatening to kill himself.''
How a domestic violence survivor changed the law
Supporting children who witness domestic violence
Mr Corley hit his wife "about the head and face with a closed fist" before pointing a handgun at her, the Aiken Standard reports, citing the arrest warrant. The violence was allegedly committed in front of an 8-year-old child.
The couple have three children.
Mr Corley told police his wife thought he was cheating on her, and he pushed her away when she attempted to strike him, the newspaper reports.
The 36-year-old attorney is known for his efforts to keep the Confederate flag flying outside the South Carolina state house.
The flag was removed in July 2015 after the massacre of nine people in a black church in Charleston by white supremacist Dylann Roof.
During a debate on the issue last year Mr Corley suggested that the Confederate flag should be replaced with the white flag of surrender.
Mr Corley was released on a $20,000 bond and could face up to 15 years in jail if convicted of both charges.
The children of a South Carolina politician accused of battering his wife can be heard screaming "just stop, Daddy" on a 911 call recording.