Abstract: The magnetic field configurations associated with the interplanetary high density structures are analyzed statistically in this paper by the superposed epoch method.The results obtained show that an average increase of about 10 degrees is observed in the inclination angle of the interplanetary magnetic field vector from the ecliptic plane.Such an increase can neither be attributed to the interplanetary streams interaction nor the inclination and wrinkle of the current sheets.Instead,it is likely that the increase would be a kind of magnetic field configuration carried by the non-steady high-density solar-wind streams.Behind the high density structures,the deviations of magnetic field vectors in the ecliptic plane from the Parker's spiral line of force are related to the high speed streams or sector boundaries.The field components parallel to the spiral line of force increase behind the high density structures when associated with the high speed streams or the sector boundaries,and,as a result,the field vectors in the ecliptic plane lie closer to the spiral line of force.