Abnormal morphology appears easily in the cross section of cold-pilgered zirconium alloy bar due to improper die design or/and improper deformation ratio distribution. Causes and its effects on usability were investigated in this paper by optical microscopy(OM), scanning electron microscopy(SEM), X-ray diffraction(XRD), hardness and density, etc. Studying results prove that such abnormal phenomena are not exhibition of defects; however result from preferred orientation with low acid corrosion resistance brought by cold pilgering; such abnormal phenomena have no effects on usability of cold-pilgered bars, cold-pilgered zirconium alloy bar with abnormal phenomena can still serve reactors safely.