The discovery of the microlensing effect has found out the new populat
ion - dark bodies having mass of the order of 0.1M. which form the hal
o of our Galaxy. There are two main criteria which identify a light cu
rve as the reveal of the microlensing effect. They are symmetry of the
light curve and equal amplification in different colors. We consider
polarization of the light beam arising in microlensing effect and find
that additional test is possible - polarization of light in the case
of a finite star disk. Consequences of polarization are also considere
d.