At the beginning of 2001,the remains of a large oval-shaped blast furnace which is the earliest and whose volume is guessed to be the biggest one of the ancient blast furnaces in oval shape unearthed in China by now and which is in a good state of preservation with clear structure,had been excavated at the Wangchenggang iron-smelting site of Han Dynasty in Lushan,Henan Province.The furnace whose inner diameter is about 4m long axis and 2.8m short axis had been ever reconstructed into a smaller hearth.The rammed earth base of the furnace and the refractory bed of the hearth had been worked well and solidly.The discharging-slag ditch which is clear and definite is the first discovery.The back system and the side systems which could be used to set up the blowing apparatuses or the instruments of filling the furnace with charge is very special.There is a big salamander in oval shape unearthed with about 30 tons weight in the front pit.All these will provide the new and very precious information for the study of the technical level of iron smelting in Han Dynasty.