Abstract : This thesis focuses on the current measurement from magnetic field measurement without using magnetic concentrator. A new current system ensuring good magnetic perturbation rejection has been realized. It consists to disposes one differential magnetic fluxgate sensor upon sections of U-shaped conductor. This conductor was crossed by the current to be measured. Using this system, we are reduced many problems of magnetic and mechanical misalignments acquired when using two magnetic sensors. Besides, using a single magnetic core permits to overcome the disparity between two magnetic sensors. This system has been studied theoretically and validated experimentally. The impacts of various factors of achievement have been studied by using analytical calculations, elements finite simulations and measurements. The integration of this current system permits the dissemination of current sensor.