  We construct boundary state and crosscap state in D=4,N=1 type-IIB Z_N
orientifold and investigate properties of amplitude. We find that the boundary
state of a cylinder is different from the boundary state of a M\"{o}bius strip.
Using these states, we find that amplitudes do not factorize in Z_N(N=even)
orientifold. Tadpole divergence remain in Z_4, Z_8, Z'_8 and Z'_{12} model due
to volume dependence of boundary and crosscap state. On the other hand the
amplitude of Z_3 and Z_7 orientifolds factorize so that we obtain the gauge
groups of the model by employing the massless tadpole cancellation condition.
