In many acoustic signal processing systems (e.g. hearing aids), directional algorithm is adopted to process signals from separated sources. However, reverberation in a living room or a conference room usually degrades noise reduction of a directional system, while the existing dereverberation algorithms can not effectively suppress interference noises. In this paper, an adaptive dual-microphone directional algorithm with two closely arranged omnidirectional microphones is proposed for reverberant environment. The proposed algorhthm combines the Adaptive Null-Forming (ANF) structure and a dereverberation algorithm based on statistical model to achieve adaptive directionality in reverberant environment. Compared with existing directional or dereverbertion algorithms, the proposed algorithm uses a simple structure to realize directionality and dereverberation synchronically, as well as owns low complexity and real-time capability. Finally, the directional performance of the proposed algorithm in reverberant enviroment was verified by simulation results.