The southern hilly and mountainous region is an important ecological barrier in south and southwest China, which is of great significance for ecological protection. With the rapid development of urbanization, it is of great strategic significance to ensure the ecological resources and ecological stability in this region for the sustainable development of China. In this study, the north region of Guangdong was taken as the study area and divided into 5 terrain gradients according to the terrain index. Then we used data of land use and social economy from 1990 to 2015 and evaluated urbanization level and ecosystem service value (ESV) in the study area on the basis of the terrain gradient by using spatial statistical methods. In addition, we analyzed the spatial correlation between the ESV and urbanization level (UL) on the terrain gradient. The results showed that (1) during 1990—2015, the urbanization level in the study area showed an uptrend, and the level of urbanization was the highest in the gradient 1 region with the terrain index between 0.003 and 0.368. (2) During the study period, the ecosystem service value the study area showed a slight downward trend. As time went on, the decline rate of ESV was the highest in the terrain gradient 1 region. The ESV increased with the increase of the terrain gradient in each year. (3) After 2000, there was the highest active transfer of land use types in gradient 1 and its surrounding regions, among which the transfer was mainly between farmland, forestland and build-up land. (4) The spatial correlation analysis showed that there was a significantly negative correlation between urbanization level and ecosystem service value in the study area, and the negative correlation was significantly increased during the study period. At the same time, they had a significant spatial aggregation effect, in which the low ESV-high UL type was concentrated in Shaoguan urban districts, Qingyuan urban districts and Nanxiong City of terrain gradient 1, and the high ESV-low UL type was mainly distributed in the minority autonomous regions with a relatively dispersed population and higher terrain gradient. This research discussed the spatio-temporal relationship between ecosystem services and urbanization innorthern Guangdong and understood the development patterns of each region, which is helpful to further understand the supporting role of ecosystem in social and economic development. The purpose is to maintain the coordination and balance between ecological protection construction and urban development, so as to safeguard and maintain the ecological value of southern hilly and mountainous region.