Employing　the　non-equilibrium　Green＇s　function　technique,　we　have　obtained　the　formula　for　dc　current　of　two　one-dimensional　multi-quantum　dot　arrays,　which　couple　to　each　other　via　tunneling　coupling　between　two　quantum　dots　connected　to　four　leads,　respectively.　The　retarded　Green＇s　function　is　a　staircase　type,　terminating　at　the　four　leads.　Furthermore,　the　four　quantum　dots　case　is　demonstrated.　The　influence　of　interdot　coupling　strength　and　quantum　dot　energy　level　on　the　transmission　probability　for　TL,　TM　and　TN　branches　is　investigated.　A　non-resonant　band　is　observed.　By　adjusting　energy　levels　of　quantum　dots,　a　resonance　emerges　in　the　region　of　the　non-resonance　band.　The　system　can　be　used　as　a　quantum　switch.