Urban tree canopy (UTC) is not only a landmark index to measure the ecological condition of a city, but also a key index to measure the achievement of forest city construction.The possible urban tree canopy (PUTC) is closely related to the formulation of scientific urban forest construction objectives.On the basis of foreign literatures and practical case studies,this paper analyzed the regional distribution and dynamic changes of PUTC within 1 km outside the 6th Ring Road in Beijing by using surface canopy interpretation data of 0.5 m resolution aerial and satellite images in 2002 and 2013.In addition, the priority of PUTC in village (community) was analyzed and evaluated by using population density, road density, and existence urban tree canopy coverage.The results showed that,during the 11 years, the PUTC in the study area decreased from 40882.18hm² to 18845.82hm². Its spatial distribution showed that the more urban centers along the loop, the less the distribution.Moreover,as time goes on, the richness of PUTC types was also getting lower and lower. By 2013, the grassland types have occupied the absolute advantage.The number of PUTC patches decreased from 109892 to 7793, but the average patch area increased from 0.37 hm² in 2002 to 2.36 hm² in 2013. The patch size pattern also changed from the absolute dominance of small patches in 2002 to a more equal situation of various types.The PUTC assessment showed that the whole study area was dominated by low and medium potential areas in 2002, accounting for 32.39% and 28.83%, respectively. In 2013, the potential pattern changed to the region with the largest area of severe low potential and low potential areas, accounting for 25.83% and 50.94%, respectively. This obviously indicated that the severe high priority and high priority areas should be the key areas for Beijing to develop urban forests in the future. The current results of potential priority assessment showed that the proportion of the severe high priority area and high priority areas reached 13.11% and 41.79%, respectively. The severe high priority areas were mainly distributed in the eastern and western urban core areas. Therefore, the future development strategy of forest canopy in Beijing urban area should take the road of joint development of the possible urban tree canopy patches and potential patches on impervious surface.