  The unparticle effects on $t\bar t$ production at the future photon collider
are investigated. Distributions of $t\bar t$ invariant mass and that for
transverse momentum of top quark with respect to Standard Model and unparticle
production are predicted. An odd valley with scalar unparticle contribution
appears for some values of $d_{\U}$, which is due to the big cancellation
between the contribution from SM and that from unparticle. This character may
be used to study the properties of scalar unparticle. Our investigations also
show that scalar unparticle may play a significant role in $t \bar t$
production at photon collider if it exists.
