A radio base station of the present invention is provided with an index setting unit configured to set an index to a radio resource in a frequency domain, a resource allocation class determining unit is configured to determine a resource allocation class of a radio communication terminal from among resource allocation classes which are classified according to radio resource allocation patterns fixedly allocated at a fixed time interval T0, based on user information of the radio communication terminal, and a resource allocation unit configured to allocate a vacant radio resource within the fixed time interval T0 to the radio communication terminal in order starting with a radio resource having an index value predetermined for the resource allocation class.