导线作为电路中的连接元件不可或缺但又常常被忽视.本文讨论了零电阻的理想导线和实际导线的性质，解释了理想导线性质的推论中的矛盾.我们可以用理想导体来理解理想导线的性质，用电阻来处理实际导线在电路中的作用.

 As a connecting element in circuit，the conductor wire is indispensable but often neglected． This paper discusses the properties of the ideal conductor wire with zero resistance and the actual conductor wire，and explains the contradiction of the deductions from the properties of the ideal conductor wire． We can take the ideal conductor wire as perfect conductor to understand its properties and take the actual conductor wire as resistor to deal with its role in circuit．