Chinese bronze artifacts of the Chou and Han periods (400BC-200AD) are highly corrosion resistant if they possess an original dark, lustrous coating. Original Chinese bronze samples and modern ones of similar composition (70% copper-25% tin-5% lead, bell metal ) were compared for susceptibility to sulfide attack (chosen to simulate an aggressive burial environment). Uncoated Chinese bronze samples have rather poor corrosion resistance, as predicted, but originally-coated ones have less than one-tenth of the permeability to H₂S of samples coated as compared to the best of today's polymer coatings, i.e., excellent corrosion resistance. The coating is not characterized in detail. -- AATA