The fractographic features of fracture surfaces which are produced by slow bend tests at various low temperatures, and the correlation between the features and the underlying microstructure are studied. V-notch specimens of mild steel SS41 are broken off by three-point slow bend tests at various low temperatures. The fracture surfaces are observed and photographed using scanning electron microscopy (SEM), and the sections perpendicular to the surfaces are observed and photographed using optical microscopy. Matching the SEM photographs to the optical micrographs, the correlation between the fractographic features and the microstructures is discussed. The drop in temperature has no effect on the relationship between the cleavage facet and the number of grains. The fractographic features of ferrite grain, as in a river pattern or cleavage step, become complex with a drop in temperature. A twin pattern occasionally makes a tongue or a cleavage step.