The　direction　of　arrival　(DOA)　estimation　is　a　key　problem　in　microphone　array　signal　processing.　The　conventional　DOA　estimation　methods　usually　are　operated　in　time-frequency　domain　based　on　the　steering　vector,　which　often　needs　to　make　a　balance　between　the　time　and　frequency　resolutions.　In　this　paper,　a　Laplace　distribution　based　DOA　estimation　method　is　proposed　by　using　Maximum　a　Posterior　only　in　time　domain.　In　this　method,　a　new　posterior　probability　model　for　speech　source　is　deduced　through　the　Laplace　prior　distribution,　which　can　modify　the　peak　of　posterior　probability　function　and　improve　the　resolution　of　DOA　estimation.　The　experimental　results　show　that　the　proposed　method　can　effectively　reduce　the　error　of　DOA　estimation　compared　with　the　conventional　methods.