China Daily quoted local reports that one of the holes, 10 meters (about 33 feet) wide and deep, appeared on a slope of the Shanghai-Kunming Highway. Details about the other one were not available.
The newspaper said roads through Yichun to Pingxiang, two cities in the province, also were closed.
About 200 villagers near the highway escaped after the sink holes appeared, but no injuries had been reported. Several houses in the area had collapsed, China Daily said.
An underground river was discovered in 2002 during the construction of the highway, the newspaper said.