Grain/domain interaction and its effect on bit formation were performed by piezoelectric force microscopy (PFM) on arrays of poled nanosize domains in Pb(Zr(0.4)Ti(0.6))O(3) thin films grown by sol-gel route. In both pulse width variation and pulse voltage variation, bit formation was observed. It was found that the grain boundary plays a role of domain growth stopper. Among two different variations, the pulse width variation only has a linear relationship between pulse width and bit size. The obtained results imply that pulse width variation is much easier to control the bit size in probe-based data storage.