copper, zinc, iron, and other nine trace elements (TEs) in 30 patients with hepatocellular carcinoma (HCC) were determined from the HCC itself and the surrounding liver parenchyma (SLP) using particle induced X-ray emission (PIXE). The result showed that the level of Zn, Fe, Co, Ca, Mn, Rb, and Cl in HCC significantly differed from that in the SLP (P<0.01), while no notable change has been observed in content of Cu (P=0.9). However, in relation to tumor size, an imbalance Cu distribution was observed. The content of Cu present in small HCC (<35mm in average diameter) was greater than that in SLP (P<0.4), and when HCC progressed to large one (>35mm in average diameter), hepatic Cu was no longer accumulated. Other elements such as Zn and Fe, showed no change in concentration relative to tumor size. The significance of the critical HCC size where a change from accumulation to loss in Cu contents is seen is also discussed.