A coaxial-cable impedance transformer used in wideband frequency range is generally restricted to the fixed impedance transformation ratio as n2:1 or 1:n2(n: the number of coaxial cables). In this paper, we propose a new coaxial-cable impedance transformer to have an arbitrary impedance transformation ratio. We have fabricated three impedance transformers($50-{Omega}$ to $25-{Omega}$, $50-{Omega}$ to $20-{Omega}$ and $50-{Omega}$ to $9-{Omega}$) to confirm the operation characteristic of the suggested impedance transformer. The reflection characteristics (S11) of the fabricated $50-{Omega}$ to $25-{Omega}$ and $50-{Omega}$ to $20-{Omega}$ impedance transformer were less than -15dB over about 3-octaves frequency range and the reflection characteristic (S11) of the fabricated $50-{Omega}$ to $9-{Omega}$ impedance transformer was less than -15dB over about 1-octave frequency range, respectively.