We report a stabilized Si3N4 simply with nanocoatings of h-BN. Very thin BN coatings are enough for suppressing the decomposition of Si3N4 particles. This approach should open up a new potential way to prepare stabilized Si3N4. Reduced nitridation of H3BO3-coated Si3N4 powder at 1050 degrees C in a flowing mixed 40% N-2+60% H-2 atmosphere, and then following heat-treatment at 1500 degrees C in a flowing N-2 atmosphere can realize the nanocoating of BN on Si3N4 particles. Compared with the Si3N4 powder without nanocoatings of h-BN, TG and XRD analysis showed that the obtained h-BN nanocoated Si3N4 powder demonstrated obviously improved stability in argon atmosphere.