[Objective] Taking the Pearl River-Xijiang River economic zone as an example, this paper analyzed the change of ecosystem pattern and evaluated its ecosystem service value in the typical east-west junction area, in order to provide a scientific basis for the construction of the regional ecological security pattern and ecological compensation research.[Methods] Based on the data of ecosystem types in the Pearl River-Xijiang River economic zone from 2000 to 2015, the change characteristics of ecosystem pattern were studied by using the annual average change rate and the transfer matrix of ecosystem types. The ecosystem service value in the research area was evaluated and analyzed in the past 15 years.[Results] ① During 2000-2015, the Pearl River-Xijiang River economic zone was dominated by forest and farmland ecosystems, and the spatial distribution pattern of ecosystems was relatively stable. The changes were mainly the expansion of the eastern artificial surface ecosystem. ② The area of farmland and grassland ecosystems decreased the most, while the wetland decreased least, and the area of the other ecosystem types increased in varying degrees. The conversion of ecosystem types mainly occurred between forest, farmland and artificial surface ecosystems. ③ From 2000 to 2015, the ecosystem service value in the Pearl River-Xijiang River Economic Zone decreased by 1.455 billion RMB, of which the value of grassland ecosystem service declined the most, while the value of forest ecosystem service increased the most. ④ The spatial distribution pattern of ecosystem service value in the counties and the districts of the Pearl River-Xijiang River economic zone was stable, but the ecosystem service value of per unit area in the eastern region showed a continuous decline trend.[Conclusion] The changes in the ecosystem pattern in the eastern part of the Pearl River-Xijiang River economic zone from 2000 to 2015 had a great impact on the decline of its ecosystem service value. In the future, it is necessary to control the expansion rate of the area of the artificial surface ecosystem in the east, to prevent the continuous decline of ecological service value.