To reduce the computational complexity of the twodimensional direction of arrival (DOA) with planar array, this paper proposes a semirealvalued MUSIC algorithm. The paper transforms one of the DOA estimation into an estimation of the angles between the target andx axis andy axis. Firstly, the real part of the received signal covariance matrix is extracted and performed an eigendecomposition to obtain the noise subspace. Then, the dimension of the process is reduced to achieve one dimension semirealvalued MUSIC spectrum. Next, the paper evaluates the estimation of the angle between the incident direction and thex axis. After that the paper utilizes the leastsquare method for getting an estimation of the angle between the target andy axis. Finally according to the corresponding relationship between azimuth and elevation and the two angles, the twodimensional DOA estimate is evaluated. This algorithm has the similar estimation performance with traditional MUSIC algorithm, significantly reducing computation complexity. The simulation results show that the algorithm is valid.