After the success of the three editions of “The International Workshop on Mobile and Cloud Computing Technologies and Security”, held successively in Rabat (2011), Agadir (2012) and Marrakesh (2013), we are proud to upgrade it as a plenary conference. CLOUDTECH’2015, “International Conference of Cloud Computing Technologies and Applications” will be held in Marrakesh on June 2-4, 2015. Cloud computing has recently gained great attention from both academia and IT industry as a new infrastructure requiring smaller investments in hardware platform, staff training, or licensing new software tools. Cloud computing can be seen as any subscription-based or pay-per-use service that, extends the Internet existing capabilities. CLOUDTECH 2015 will address topics related to cloud technologies; architecture and applications including distributed computing and data centers, cloud infrastructure and its security, end-user services. The conference will provide a high-level, international forum for scientists, researchers, professionals and students who will have the opportunity to present state-of-the-art research results, address new challenges, and discuss trends in Cloud Technology and applications.