Abstract: Using two dimensional three component dissipative MHD model,a numerical simulation is presented concerning the current formation process in a quadrupolar potentiel magnetic field caused by photospheric shear motion. Separator plays a key role in the evolution Of the magnetic field f Current mainly builds up in separatrices and the magnetic loops in which the foot shear gradient is muximum.In separator;the current density reaches its maximum value.The photospheric shear inchon may lead to Separator splitting into strong current sheet,parallel or vertical to photosphere, depending on the location and gradient of the shear.