Moody's, a rating agency with huge global financial market influence, cut South Africa debt rating from "Baa1" to "Baa2" on Thursday.
In Moody's downgrade report, South Africa's medium-term economic growth prospect deteriorates and public debt is rising.
The report shows that ongoing electricity shortages, rising interest rates and worsening investing climate are among the structure weaknesses of South Africa.
As reported by local TV media CNBC, South Africa's government made a quick response to the rating cut, and said it is committed to narrowing its budget deficit and recognized the need to implement measures to boost economic growth.
"Government will continue to make the tough decisions that are necessary to address our challenges so we can build on the gains we have made over the past 20 years to improve the lives of our people," the Treasury said.