It is an object to provide a sequence allocating method that, while maintaining the number of Zadoff-Chu sequences to compose a sequence group, is configured to make it possible to reduce correlations between different sequential groups. This method comprises the steps of setting a standard sequence with a standard sequence length and a standard sequence number in a step, setting a threshold value in accordance with an RB number in a step, setting a sequence length corresponding to RB number in a step, judging whether ¦r/N−rb/Nb¦=Xth(m) is satisfied in a step, including a plurality of Zadoff-Chu sequences with a sequence number and a sequence length in a sequence group in a step if the judgment is positive, and allocating the sequence group to the same cell in a step.