A partially hyperbolic diffeomorphism f has quasi-shadowing property if for
any pseudo orbit xkk∈Z, there is a sequence of points
ykk∈Z tracing it in which yk+1 is obtained from
f(yk) by a motion τ along the center direction. We show that any
partially hyperbolic diffeomorphism has quasi-shadowing property, and if f
has C1 center foliation then we can require τ to move the points along
the center foliation. As applications, we show that any partially hyperbolic
diffeomorphism is topologically quasi-stable under C0-perturbation. When f
has uniformly compact C1 center foliation, we also give partially hyperbolic
diffeomorphism versions of some theorems holden for uniformly hyperbolic
systems, such as Anosov closing lemma, cloud lemma and spectral decomposition
theorem