With the acceleration of urbanization and human activities, the quality of urban ecological environment and its ability to support human social and economic development are being seriously degraded. More and more attention has been paid to the study of urban ecosystem and its changes, and a large number of long-term monitoring work of urban ecology has emerged, but there is little discussion on the monitoring methodology. Ecological monitoring is the process of multiple (continuous) observations of ecosystems to collect information on the status and changes of ecosystem elements, structures, processes, functions, and services in different time and space, providing basic data and decision-making basis for ecosystem evaluation, restoration, and management. The main tasks of long-term monitoring of urban ecology include: (1) building a long-term investigation and observation system for urban ecosystems, including monitoring systems for major environmental factors, ecological investigation sample plots, ecological processes and functional observation systems, etc. (2) observing urban ecosystem elements, structures, processes and functional states and their changes, (3) collecting information on human interference and management in cities, (4) Collecting and preserving urban environment and biological samples, and (5) providing and publishing information and warnings on urban ecological environment and its changes. Based on the revies of the types and practical experiences of long-term ecological monitoring, and focusing on the main tasks of long-term monitoring of urban ecology, this paper constructs the overall thinking framework of "stress+demand-ecosystem response" for long-term monitoring of urban ecology from the perspective of environmental stress and the requirement of urban construction management, and summarizes 7 core fields (land cover/use, human habitat quality, biodiversity, biomass production, hydrological process, biogeochemical cycle, and material metabolism) based on the factors, patterns and processes of urban ecosystem which are the most basic in science and the most concerned in society. The paper also analyzes 4 methods of long-term monitoring of urban ecology, including remote sensing, instrumentation, field survey and citizen science. And it points out the long-term monitoring unit of urban ecology and its spatial layout and monitoring frequency. Long term monitoring of urban ecology also requires determining appropriate long-term monitoring locations, indicators, and frequencies based on the size of the monitored city, socio-economic development level, biogeographic background, and monitoring capabilities. With the increasing understanding of the structure and processes of urban ecosystems, as well as their spatiotemporal changes, and the development of urban socio-economic conditions, it is necessary to update the scientific issues of long-term monitoring of urban ecology, select more scientific indicators, and establish a more reasonable monitoring system for long-term monitoring. The paper will provide a methodological basis and practical reference for the long-term monitoring of urban ecology in China.