The bronze-iron bimetallic objects unearthed from the Guo State Cemetery in Sanmenxia City are evidences of early use of iron in China’s Central Plains areas. This paper carries out scientific analyses of 3 bimetallic objects from tomb No. 2009 of this cemetery using metallography microscopy, Scanning Electronic Microscope-Energy Dispersive X-ray Spectroscopy (SEM-EDS) and Electron Microprobe (EMPA). It is revealed that the iron blade of spear head (STG001) was made of bloomery iron. Multiple-phased inclusions of silicate and iron oxide were elongated during the manufacturing process and arrayed along the deformation directions. Residue iron pills in the knife (SGT002) and the Ge Blade (SGT003) were found to be content notable Ni and a few of Co, and the result of line scanning analyses by the SEM-EDS shows interval distribution of nickel among different phase, indicating the meteoritic origin of the iron metal used to make the blades. The original Ni content of the meteoritic iron would fall in the ranges of IIIC and IIID types which will give the meteorites a microstructure of Finest (Off) or Ataxite. Metallography of bronze part of samples SGT001 and SGT 002 were observed to be typical as-casting microstructure of tin bronze with corroded α solid solution matrix and dispersed particles of (α+δ) eutectoid. The fact that there is no sign of deformation and recrystallization at the interface of iron and bronze parts indicates no further mechanical processing had been applied in the joint region. It is then inferred that the pre-made iron blades by were embedded into the casing mould and connected with bronze part by a cast-on process. On the basis of analytical results, this paper also briefly reviews the early use of iron metal in China and points out that the co-occurrence of meteoritic and manmade iron in the Guo State Cemetery demonstrated that this period had been a crucial stage in the development of iron metallurgy in China. The Northwest Region of China had played an important role during the transmission of early bloomery iron metallurgy while the establishment of cast iron technology in China’s Central Plains area would have a close relationship with the pre-existed technological tradition of bronze casting during the Shang and Zhou Periods.