The　present　work　aims　to　study　the　free　vibration,　buckling　and　post-buckling　behaviors　of　bidirectional　functionally　graded　(BDFG)　microbeams.　The　material　properties　of　a　BDFG　microbeam　were　varied　continuously　in　both　thickness　and　axial　directions.　Furthermore,　four　different　kinds　of　material　distribution　function　were　taken　into　consideration,　two　of　which　were　symmetrical　in　the　thickness　direction,　and　the　remaining　two　were　asymmetrical.　Employing　the　Timoshenko　beam　theory　and　the　consistent　couple　stress　theory　(CCST),　the　governing　equations　and　associated　boundary　conditions　of　BDFG　microbeams　were　formulated　by　Hamilton＇s　principle.　The　differential　quadrature　method　(DQM)　and　Newton＇s　method　were　applied　to　solve　the　eigenvalue　problems　and　buckling　path,　respectively.　Finally,　several　parametric　investigations　were　carried　out　to　probe　the　influence　of　material　distribution　functions,　length　to　thickness　ratio,　gradient　indexes　and　size　effect　on　the　vibration　and　buckling　behaviors　of　BDFG　microbeam　under　different　boundary　conditions.