  In recent years various models for the Galactic distribution of massive
compact halo objects (MACHOs) have been proposed for the interpretation of
microlensing toward the Large Magellanic Cloud (LMC). A direct way to fit the
best model is by measuring the lens parameters, which can be obtained by
measuring the Einstein crossing time and the parallax effect on the
microlensing light curve and by astrometry of centroids of images. In this
work, the theoretical distribution of these parameters is obtained for the
various power-law Galactic dark halo models and MACHO mass functions (MF). For
self-lensing as one of the models for the interpretation of LMC events, the
maximum shift of image centroids and the parallax parameter are one order of
magnitude smaller than for models with dark halos. This can be used as a test
for the self-lensing, although the shifting of image centroids 0.02 {\it mas},
for the LMC events is unlikely to be observed by the astrometric missions such
as FAME, GAIA and SIM.
