At least 515 endangered rhinos have been poached so far this year in South Africa, the government said.
The latest figure showed the Kruger National Park continues to be the hardest hit, with 321 rhinos killed since January, Xinhua cited the Department of Environmental Affairs as saying in a report.
The Kruger park is the largest reserve in South Africa.
The report warned that "South Africa's rhino population will rapidly decline in the next three years if it is not protected and poaching is not eradicated".
South Africa is home to the largest rhino population of about 20,000 in the world, accounting for nearly 80 percent of the global total.
In 2012, a record 668 rhinos were slaughtered in South Africa, compared to 333 in 2010 and 448 in 2011.
The government has intensifying the crackdown on rhino poaching. More than 140 poachers have been arrested this year.
