Stable colloidal systemscomposed of adouble surfactant water-based magnetic fluid mixed with a cationic isotropic micellar solution of cetyletrymethyleammonium bromide (CTABr) are prepared for different concentrations of magnetic fluid.The structural integrity between nanomagnetic particles of magnetic fluids and soft micelles is investigated using themagneto-optical techniques like magnetic birefringence, transmission and relaxation measurements.Magneto-optically induced retardation and relaxation measurement indicates the existence of magnetically induced interactions in this mixed system.Similar behaviour is also observed in small angle neutron scattering experiments