Abstract: Uncertainties,especially the uncertainties of human behavior,introduce great challenges to energy transition analysis.This paper discusses the nature of uncertainty in terms of randomness and vagueness;analyzes the sources of uncer-tainty in terms of model and parameters,operation conditions,disturbances（failures）,viewpoints of stakeholders,and human behaviors;and classifies the uncertainty into different categories based on cognitive level.The-state-of-the-art of uncertainty analysis approaches for energy transition and their limitations are reviewed.Aiming to address the chal-lenges introduced by large amount of uncertainties with various characteristics,a comprehensive analysis framework that integrates multiple approaches is proposed to give consideration to both the rapidity and accuracy of the uncer-tainty analysis simultaneously.