Drawing from the organizational theory,this study builds an analytical frame work for the data-sharing dilemma and conducts an analysis of the Big Data Bureau of J.City and Big Data Center of W.city.This study finds that the fragmentation of data-providing departments and the divergence of the data standard,data security,and risk avoidance,and other sharing dilemmas have different impacts on the two agencies of data governance.This is because the transaction costs between the two organizational structures varies in various institutional contexts such as the cost of data sharing,the capacity of accountability,agency benefits,and internal incentives are different for the two agencies of data governance.Dynamic changes in transaction costs lead to different results of data sharing.As a result,the policy suggestions are put forward from the perspective of organization structure and institution to enhance data sharing across government agencies.