  We consider the modified restricted three body problem with power-law density
profile of disk, which rotates around the center of mass of the system with
perturbed mean motion. Using analytical and numerical methods we have found
equilibrium points and examined their linear stability. We have also found the
zero velocity surfaces for the present model. In addition to five equilibrium
points there is a new equilibrium point on the line joining the two primaries.
It is found that $L_2$ and $L_3$ are stable for some values of inner and outer
radius of the disk while collinear points are unstable, but $L_4$ is
conditionally stable for mass ratio less than that of Routh's critical value.
Lastly we have obtained the effects of radiation pressure, oblateness and mass
of the disk.
