Vegetation provides many environmental benefits to the city, and daily access to vegetation contributes to the well-being and psychological status of urban residents. Understanding and measuring urban dwellers’ view-based exposure to greenery has become an important task for assessing the quality of urban life. This paper presents a quantitative and objective indicator, Floor Green View Index (FGVI). It is defined as the area of visible urban vegetation on a particular floor of a citybuilding. The method for estimating FGVI consists of three steps: creating observation points and setting observation platform for each detected floor, conducting viewshed analysis and extracting visible urban green space, and computing Floor Green View Index. The method is proposed and tested through a case study of the Lujiazui region, Shanghai, China, using airborne Light Detection and Ranging (LiDAR) data and aerial photographs.