In the previous study, it was found that urban heat island intensity in National University of Singapore (NUS) campusas high as 4oC at around 13:00. It is also concluded that the presence of dense greenery in NUS environment is very important in keeping low ambient temperature.National University of Singapore has announced its new master plan in 2005, entitled NUS Master Plan 2005. Many new buildings will be built and in some areas existinggreenery will be removed. Geographical InformationSystem (GIS) was use to evaluate the greenery condition.It was found that the greenery rate of NUS Master Plan 2005 will drop by about 3% from 55.10% of NUS current condition to 52.31%. In order to have a sustainableenvironment, the greenery condition should be at least maintain at the same rate or even make it better.For this purpose, potential of increasing greenery area by rooftop greenery application was also done. The targetis to maintain the green rate of different zones at the same rate with current condition. In total, there will be more than 56% new buildings in NUS Master Plan 2005. Therefore, there is a good opportunity to plan and introduce the rooftop greenery or vertical greenery since in the early design stageThe ENVI-Met simulation predicts that the ambient temperature in NUS environment will increase about 1oC when NUS Master Plan 2005 is completed. It is due to the reduction of greenery rate.