Polarized three-dimensional fluorescence spectra of different kinds of milk were measured, including pure milk, milk with high calcium, and milk with high calcium but low fat produced by YiLi and MengNiu. It was found that the fluorescence intensity is stronger when excitation and emission polarizer orientation is parallel. The angle between excitation dipole and emission dipole of all kinds of milk equivalent chromophore was estimated by a simple model, indicating that they all less than 40°. The angle for milk with high calcium but low fat is less than that of pure milk and milk with high calcium. And in the experiment, the polarized fluorescence intensity of milk with high calcium but low fat is significantly greater than the others, which fitted with the model estimation.