Abstract: Hysferesis error is one of the most important factors by which the precision of the magnetoelastic effect force transducer is affected. For the s-ake of investigating the origin of the hysferesis error, a 3%Si-Fe cold rol- led single oriented electric sheet sample was used. In the mesurement region of the sample, there was only one crysial. The results showed that bot-h of the magnitude and the type of the hysferesis error of the sample varied with θ,the angle between the100 of the crystal and the direction of the stress a.There were two kinds of hysteresis error,one of which was positive and the other negative. In this article the authors analysised the processes of the change in magnetic domains distribution of the sample. It seems that the variation of the magnitude and type of hysteresis error of the sample is due to the interactions between domain walls and crystal defects, particularly dislocations.