The effect of pulverizing methods on sintered strength of degraphitized gray cast iron swarf was investigated. The main results are as follows: 1) The compressive fracture strength level of sintered cast iron powder is in the order of cutter mill powder, mortar grinding powder and ball mill powder; This is considered to be due to the increase in surface roughness. The increase in surface roughness factor leads to the increase in green strength and sintered strength. 2) The compressive fracture strength of sintered products which were compacted at 12t/㎠ and sintered at 1150℃ for 90min in the vacuum atmosphere, is higher than that of parent gray cast iron by the factor 2.5. 3) The increase in sintered strength is due to the spheroidal graphite precipitation at the finely dispersed round pore.