Abstract: The real atmosphere is always under complicated conditions. Thereby problems caused by complicated conditions have imposed greatest scientific challenges in land-atmosphere interaction study. Application of research achievements in this field for solving various problems related to weather and climate are severely restricted. This paper presents an overview of recent developments in the study of complicated land-atmosphere interaction in China, and the complicated land-atmosphere interaction is discussed. Mechanisms for land-atmosphere interaction under complex conditions are explored from the perspective of both the land surface and the atmospheric boundary layer processes, which are two critical components of the land-atmosphere interaction. Key problems in land-atmosphere interaction studies under complicated conditions are addressed. Meanwhile, the basic method to investigate land-atmosphere interaction with a focus on complicated land surface processes and non-uniform atmospheric boundary layer has been outlined. Suggestions for further research activities of land-atmosphere interaction have been proposed.