Objective: To investigate the therapeutic efficacy of Gandou Tablet Ⅰ (肝豆片Ⅰ号) in treating hepatolenticular degeneration (HLD) and its effect on urinary trace element in 24 hours. Methods: Thirty four patients with HLD took Gandou Tablet Ⅰ for 4 weeks, their changes of symptoms, signs and daily life pattern were observed closely, and the levels of urinary trace element in 24 hours before the therapy and every week after initiation of treatment were measured. Results: The total effective rate reached 70.59%, with markedly effective rate being 8.82%.The therapeutic effect was much better in the child and mild patients. After treatment, the daily urinary copper output was obviously increased every week compared with that before ( P < 0.01 ). Although it was highly negative linear correlated with the duration of treatment (γ=-0.96, P < 0.05 ), it has insignificant difference between any two weekly excretion of urinary copper per 24 hours after treatment ( P >0.05). So its effect on urinary copper excretion was not decreased. Conclusion: Gandou Tablet Ⅰ could increase the output of urinary copper, hence it was effective in treating HLD without apparent toxic or side reaction. Objective: To investigate the therapeutic efficacy of Gandou Tablet I in treating hepatolenticular degeneration (HLD) and its effect on urinary trace element in 24 hours. Methods: Thirty four patients with HLD took Gandou Tablet I for 4 weeks , their changes of symptoms, signs and daily life pattern were observed closely, and the levels of urinary trace element in 24 hours before the therapy and every week after initiation of treatment were measured. Results: The total effective rate reached 70.59% with markedly After treatment, the daily urinary copper output was even increased during every week compared with that before (P <0.01). Although it was highly negative linear correlated with that the duration of treatment (γ = -0.96, P <0.05), it has insignificant difference between any two weekly excretion of urinary copper per 24 hours after treatment (P> 0.0 5). So its effect on urinary copper excretion was not decreased. Conclusion: Gandou Tablet I could increase the output of urinary copper, hence it was effective in treating HLD without apparent toxic or side reaction.