The invention provides a clock signal transmission method in radio communication apparatus, and radio communication apparatus. The radio communication apparatus includes a transmission clock signal generation part, when a harmonic component of a first clock signal used by a clock signal using part agrees with a reception frequency of the radio communication apparatus, generating a second clock signal different from the first clock signal; a clock signal transmission part transmitting the second clock signal, generated by the transmission clock signal generation part, for the clock signal using part, and a use clock signal generation part generating the first clock signal from the second clock signal, transmitted by the clock signal transmission part, and provide the generated first clock signal to the clock signal using part. In the radio communication apparatus, when a harmonic component of a clock signal falls within a reception frequency, possible reception interference can be effectively avoided.