The influence factors of biochar stability are discussed on the basis of its concept,and the research methods and prediction models of biochar stability are comparatively analyzed.The results show that the stability of biochar is attributed to highly aromatic structure and protective effect of soil aggregates.The main factors affecting biochar stability are temperature,raw materials and environmental conditions.The optimal evaluation method for biochar stability is to combine the isotope labeling with double exponential model.Then,it is pointed out that different types of soil,crop rotations and prediction model is the development direction of current biochar stability research.