Park rangers found eight dead rhinos in the park in just one day last week, the BBC reported Monday.
South Africa is a magnet for poachers because it has the largest population of rhinos in the world, with about 20,000 animals. That represents 70 percent to 80 percent of the world total, conservationists said.
In 2011, 448 rhinos were killed in South Africa, more than half of them within the boundaries of Kruger Park.
The recent spike in rhino killings is being blamed on growing demand for rhino horn in Asia, where it is believed to be a remedy for various illnesses, including cancer.
South African Environment Minister Edna Molewa said the new rangers in Kruger, one of South Africa's top tourist destinations, would bring the total to 650.
A 95-mile electric barrier will be built along the border with Mozambique, where many of the poachers are believed to come from, authorities said.