In order to study the mechanical behaviors of post-tensioned unbonded prestressed concrete hollow flat floors,a 1 /4 scale post-tensioned unbonded prestressed reinforced concrete hollow slab-column structure model was made and test under the uniformly distributed load on the plate was done. The test results showed that the floor had a certain load carrying capacity. The deflection of concrete hollow flat floor by vertical load was abowlshape. The point of maximan displacement was in the middle of concrete hollow flat floor. By means of finite element analysis methods,the calculation results showed that post-tensioned unbonded prestressed concrete hollow flat floor existed anisotropy with parallel circular-tubes. In parallel tube direction,the continuity of plate was destructed and the stiffness of the plate was decreased greatly. The plate deformation could still be regarded as continuous cross-plate in parallel tube directions and in vertical tube direction.