Low carbon steel specimens cold rolled at ratios of 0–40 % have been examined comprehensively by magnetic Barkhausen noise (MBN) method, and their microstructure were studied by transmission electron microscope. In order to correlate MBN parameters with those mechanical properties, Vickers hardness and ductile-brittleness transition temperature (DBTT) were also evaluated. MBN energy and rms voltage rise rapidly with cold rolling below 10 %, and saturate at higher rolling ratio. This phenomenon is attributed to the combined effects of cell texture and dislocation density. It is also found that good correlation between MBN parameters and Vickers hardness, DBTT.