  The results of three-dimensional numerical simulations of mass transfer in
semidetached binaries after mass transfer termination is presented and the
structure of residual accretion disk was investigated. It was shown that after
the mass transfer termination the quasi-elliptic accretion disk becomes
circular. It was also shown that the cessation of mass transfer results in
changing of the structure of the accretion disk: the second arm of spiral shock
is appeared as well as a new dense formation (blob), the latter moving through
the disk with variable velocity. The blob doesn't smear out under the action of
dissipation but is sustained by interaction with arms of spiral shock for
practically all the lifetime of the disk.
  We also analyze the dependence of disk's lifetime on the value of viscosity.
For the value of parameter $\alpha$ that is typical for observing accretion
disk ($\alpha\sim0.01$) the lifetime of residual disk is found to be equal to
50 orbital periods.
