This paper proposes an interchannel correlation (ICC) estimation method that can enhance the performance of the spatial audio coding such as Parametric Stereo of HE-AACv2 and MPEG Surround. Conventional ICC estimation methods assume that phase differences between two channel signals are constant in parameter bands and those phase differences are compensated to maximize the ICC. The proposed method introduces robust ICC estimation by compensating constant interchannel time difference (ICTD). ICTD is estimated from interchannel phase difference (IPD) and linear phases corresponding to ICTD are compensated. ICTD is Simulation results show that the proposed method provides more accurate ICC’s than the conventional methods.