Aging effect due to domain evolution in (K-0.5,Na-0.5)Nb0.97Sb0.03O3 < 001 > textured ceramics was investigated by piezoresponse force microscopy. We find that aging effect is pronounced in the orthorhombic single phase field. A more uniform and finer domain structure on the order of several hundred nanometers was observed after aging and is believed to originate from defect-migration. After poling, large domains (similar to 10 mu m) with smooth boundaries were found in the aged condition due to the more readily redistribution of uniform and finer domain structures after aging. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3698154]