Objective To analyse the concentrations of 21 elements in 24 h urine of patients with Wilson's disease (WD) during penicillamine therapy. Methods Forty patients with WD undergoing penicillamine therapy and hypocopper diets were collected (WD group), and another 12 healthy people were served as control group. The concentrations of 21 elements of Cr, Fe, Co, Se, Mn, Cu, Zn, As, Be, Al, V, Ni, Cd, Sb, Ba, Pb, Ti, Th, U, Ca and Mg in 24 h urine were determined by inductively coupled plasma mass spectrometry. Results For 7 essential trace elements (Cr, Fe, Co, Se, Mn, Cu and Zn), the concentrations of Mn, Cu and Zn in 24 h urine of WD group were significantly higher than those in control group (P<0.05, P<0.01 and P<0.01). For 12 unessential trace elements (As, Be, Al, V, Ni, Cd, Sb, Ba, Pb, Ti, Th and U), the concentration of As in 24 h urine of WD group was significantly higher than that in control group (P<0.05). For 2 macroelements (Ca and Mg), the concentration of Ca in 24 h urine of WD group was significantly higher than that in control group (P<0.001). Conclusion For patients with WD undergoing penicillamine therapy and hypo-copper diets, the concentration of Cu in 24 h urine increases, and those of Mn, Zn, As and Ca also change.