Abstract: Based on the accountability results of 203 public officials who were held accountable in 22 environmental pollution events during 2007-2017， this paper analyzes the main factors that affect the severity of officials accountability from the three dimensions of accountability subject， accountability object and accountability reasons by using Ordinal logistic regression method. The research shows that official liability type is the key factor in determining the official accountability; the rank of position， the involvement of the government rank， and the severity of environmental pollution event have a significant impact on the accountability of officials; the pressure of public opinion is related to the results of accountability but its impact is not significant. The analysis shows that the implementation of accountability of officials of environmental pollution events in China is in general relatively more standardized， but there are still some problems， such as the unclear definition of different types of liability in environmental accountability laws and regulations， weak accountability to the high-level officials， and the lack of local government environmental accountability， etc. Therefore， it is important to further strengthen the officials accountability system， enhance the guidance and supervision of the central government on the accountability of local governments， and institutionalize social accountability to promote the transformation of China's environmental accountability into a rule of law and normalization.

Key words: environmental pollution event, public officials accountability, accountability result, social accountability