Abstract: The deformations of cavitation bubbles in the central region of clusters under their superstrong expansion and compression are studied. The conditions close to those in the well-known experiments on the acoustic cavitation of deuterated acetone are assumed. The simplest model of a cluster composed of seven initially spherical bubbles, the centers of which are located on three mutually perpendicular lines intersecting each other at a single point, is applied. The lateral bubbles are equidistant from the central one, the center of which is the intersection point of the lines. For comparison, the simplest model of a streamer composed of three bubbles on the same line is also considered. It has been established that the maximum deformations of the central bubble in the case of a cluster proves to be two orders of magnitude smaller than for a streamer. At that, in both a cluster and a streamer, the central bubble is deformed only in the form of spherical harmonics with even numbers and, and while the maximum deformations turn out to be in the form of second harmonics in the case of a streamer, the fourth-harmonic deformations are maximal in the case of a cluster.