Electroplating of copper is widely used for the fabrication of interconnections of printed circuit boards, in which via-holes are used to connect conductive layers. Self-annealing is an important feature of electroplated copper which significantly alters its microstructures. The degradation of 〈110〉 texture and the enhancement of 〈311〉 texture in electroplated copper during self-annealing process are observed by X-ray diffraction (XRD) and electron backscattering diffraction (EBSD). The mechanism of this transformation is discussed and illustrated.