The South China Sea feature is also claimed by the Philippines and is a major source of tension between the two countries
Beijing has controlled the shoal – which it calls Huangyan Island and is known as the Panatag Shoal in the Philippines – since a stand-off with Manila in 2012.
The State Council, China’s cabinet, said the establishment of the national nature reserve was “an important measure to preserve the diversity, stability and sustainability of the island’s natural ecosystem”.
In a statement to the Ministry of Natural Resources, it said relevant authorities “should hold a strong commitment to ecological and environmental protection responsibilities”.
“Enforcement efforts against illegal activities related to the nature reserve should be strengthened,” it said.