Abstract: 【Objective】Currently, there is considerable interest in the issues of urban heat island because of the rapid pace of urban sprawl. Urban green land has the potential to reduce land surface temperature, but vegetation phenology is affected by long-term high temperatures in the urban heat island. In this study, we aimed to research the effects of urban heat island on vegetation phenology by comparing the vegetation phenology within and outside the urban heat island of Nanjing City. 【Method】To achieve this goal, the thermal bands of Landsat 8 images were used to estimate the land surface temperature, and the hot and cold spots of the land surface temperature were spatially analyzed to identify the urban heat island, which is a cluster of high land surface temperatures(hot spot of temperature)in Nanjing. The start and end of the growing season for vegetation inside and outside the urban heat island were estimated using Normalized Difference Vegetation Index(NDVI)curve extracted from MOD13Q1 images. 【Result】The results show that the images of the land surface temperature in summer were more effective in identifying the urban heat island. The start of the growing season of the vegetation on the urban heat island is earlier than that of the vegetation outside the urban heat island, and the end of the growing season in urban heat island is later than that outside the heat island. The growing season of the vegetation on the urban heat island of Nanjing is 20 days longer than that of the vegetation outside the urban heat island. 【Conclusion】The phenomena for green vegetation to adapt to the long-term urban heat island effects are that the start of the growing season is earlier, the end of the growing season is later, and the growing season is longer.