On the basis of its color-magnitude diagram NGC 6528 is one of the two most metal-rich globular clusters that have so far been found in the Galaxy. Such a conclusion is consistent with Morgan's metallic line-strength classification of the integrated spectrum of this cluster. The reddening of NGC 6528 is estimated to be E(B-V)=0.52+/-0.07, from which R=6.1kpc and Z=-0.4kpc.