As the breakthrough of Chinas further administrative reforms, the Super-Ministry reform is aimed to serve the public better by constructing a service-oriented government which has become a consensus in academia.The paper will research the pioneering traffic and transport reforms in Guangdong, Chongqing and Beijing districts taking the variable-oriented strategies of cross-case analysis.These reforms are under the direction of separation of government from market, separation of the functions of the government from those of enterprises, state assets management authorities, public institutions, separation the power of the central government from that of the local governments.In the research, we conclude that these pioneering traffic and transport reforms as the "diagonal" mode which could also be borrowed by the other districts of China.This paper agrees that cross-case analysis with its advantage in studying the super-ministry reform could reach a more generalized conclusion by means of various cases while the thoroughness and completeness of within-case study can be held.This approach could be employed effectively in both generalization of top-down local reform and population of the administration modes.