Transect research is being a focus of IGBP in recent years.The paper answered the reasons for research on transects and their distribution and respective research objects on the globe,especially detaily discussed the two transects among them,American' s OTTER and China' s NECT.The finish of the OTTER has indicated that the mechanistic models,such as Forest-BGC,even they need numerious environmental variations to run them,most variations can be deduced via the way of remote sensing.This enables us to develop mechanistic models at regional level,Thus improves their manipulation and in the meantime ensures their simulation accuracy.The ongoing Chinese northeast transect has also had many progresses in the decision on Ecotone area,setting up spatial simulation model and deducing parameters of the model from NDVI and so on.