E-Government is not a new thing in the world of ICT. But how if the e-government combined with cloud computing, it would give something new. This book is about how cloud computing can be harnessed for the benefit of e-government, and also provide an explanation of basic concepts in building e-government oriented to the concept of cloud computing. Things discussed in this book is the theory of Cloud Computing, SOA, Web Services technologies, e-government, Prototype cloud computing for e-government, and how to migration from classical e-government toward the e-govenment based cloud