A method and an apparatus for estimating direction of arrival of radar reception signal using antenna array extrapolation. Obtained is a transformation matrix representing a relationship between phases of reception signals received through ith to (N−2+i)th antennas and a phase of a reception signal received through (N−1+i)th antenna in a ULA antenna unit including N actual antennas. A phase of a virtual reception signal received through a new (N+i)th virtual antenna is generated by multiplying values corresponding to phases of the reception signals received through (i+1)th to (N−1+i)th antennas by the transformation matrix. A magnitude of the virtual reception signal received through the (N+i)th virtual antenna is obtained by averaging magnitudes of the reception signals received through ith to (N−1+i)th antennas.