We investigated turbulent flow around building arrays of four different building aspect ratio (H/W) using large eddy simulation. This simulation was aimed to study the similarity of urban canopy flow and plant canopy flow which was expected with the increase of building aspect ratio. As aspect ratio increased, the streamwise flow speed within the urban canopy decreased. Drag coefficient of urban canopy increased with aspect ratio. This is probably due to the increase of frontal area index and the occurrence of transverse flow along the streets. According to quadrant analyses and turbulence statistics, momentum transfer became more efficient as aspect ratio increased. At a high aspect ratio, momentum was more effectively transferred at cross sections than gaps.