  We computed proper motions of a selected sample of globular clusters
projected on the central bulge, employing CCD images gathered along the last 25
years at the ESO-NTT, ESO-Danish and HST telescopes. We presented a method to
derive their proper motions, and a set of coordinate transformations to obtain
3D Galactic velocity vectors of the clusters. We analysed 10 globular clusters,
namely Terzan 1, Terzan 2, Terzan 4, Terzan 9, NGC 6522, NGC 6558, NGC 6540,
AL~3,ESO456--SC38 and Palomar 6. For comparison purposes we also studied the
outer bulge cluster NGC 6652. We discuss the general properties of the
proper-motion-cleaned Colour-Magnitude Diagrams, derived for the first time for
most of them. A general conclusion is that the inner bulge globular clusters
have clearly lower transverse motions (and spatial velocities) than halo
clusters, and appear to be trapped in the bulge bar.
