Abstract: Many artificially modulated signals exhibit a cyclostationarity (or periodic correlation) property which corresponds to the underlying periodicity arising from carrier frequencies or baud rates. In this article a new two-dimensional direction-of-arrival (DOA) estimation method is proposed which exploits the conjugate cyclostationarity of the signal to improve the DOA estimation performance. By properly combining the spatial information with the temporal conjugate cyclostationarity of the signal, the optimal lag selection problem can be avoided, and the array aperture can be considerably extended. Consequently, an improvement of the DOA estimation resolution is achieved，even with low signal-to-noise ratio. Furthermore, the two-dimensional searching and parameter pairing processes are avoided. Computer simulations are conducted to show the efficiency of the proposed method.

Key words: array signal processing, two-dimensional direction-of-arrival, cyclostationarity, conjugate cyclic correlation, dual parallel uniform linear array