On the basis of the consideration that the magnetic-field-induced opti
cal anisotropy caused by the combined effects of field-induced orienta
tion of shape-anisotropic scatterers and the chain-like aggregation of
magnetic particles in external magnetic field, a unified mathematical
expression is established and Monte Carlo technique is implemented to
simulate the field dependence of magnetobirefringence. Compared with
the previous models, this method is more effective in exposing the mic
ro-origin of the phenomena and can be easily extended to calculate oth
er aspects of the effects.