One Russian analyst thinks the Chinese have a lot more warheads than the U.S. assumes:
China has nearly 750 theater and tactical nuclear warheads in addition to more than 200 strategic missile warheads, a stockpile far larger than U.S. estimates, according to a retired Russian general who once led Moscow’s strategic forces.
New details of China’s strategic and tactical nuclear warheads levels were disclosed by retired Col. Gen. Viktor Yesin, former commander of Russia’s Strategic Rocket Forces, during a conference several months ago. A copy of Yesin’s paper was translated last month by the Georgetown University Asian Arms Control Project and obtained by the Washington Free Beacon.
Either way, the "consensus" appears to be that China has about 240 nuclear weapons (give or take a hundred).