Abstract: The attitude stability of flexible spacecrafts is reduced because of micro vibrations resulting from rotating attitude control actuators. In this paper, the concentrated vibration isolation and the distributed vibration isolation are studied in the context of high stability pointing. At first, the attitude dynamics model for the flexible spacecraft containing vibration isolators is established. Then, the performances of the passive concentrated vibration isolation and the distributed vibration isolation for the attitude actuators are compared by using the simulation method. It is indicated that by using high-stiffness isolators, the concentrated vibration isolation has a similar performance as the distributed vibration isolation in the satellite maneuvering processes. Using the low-stiffness isolators, the concentrated vibration isolation loses stability more easily than the distributed vibration isolation. The concentrated and distributed vibration isolations have similar performances for attitude stabilizing with both the high-stiffness or the low-stiffness isolators.