A new oil pressure sensor has been developed utilizing iron base amorphous magnetic alloys. The sensor was composed of a cylindrical body with oil inlet, the amorphous magnetic alloy strip glued around the body and coils arranged to the alloy.The output behavior of the sensor was explained successfully by applying a rotation magnetization model. The characteristics of the developed sensor were as follows. Measurable pressure range; 0 to 20MPa. Operating temperature range; -30 to 100°C Inaccuracy; less than 2 %F.S. (F.S. means full scale) The durability tests like cyclic heating or pressure application demonstrated that the developed sensor is durable enough for automobile use.