Big Data and Cognitive Computing (ISSN 2504-2289) is an international, interdisciplinary scholarly scientific, and open access journal on big data and cognitive computing for computer science. In the past decade, the computer and information industry has experienced rapid changes in both platform scale and scope of applications. Computers, smart phones, clouds, social networks, and supercomputers demand not only high performance but also a high degree of machine intelligence. As a matter of fact, we are entering an era of big data and cognitive computing. In the big data era, successful cloud systems, web services and supercomputer centers must be designed to discover, store, process, learn, analyze, and predict from a massive amount of data. To face these new computing and communication changes, we must upgrade the clouds and the computing ecosystem with new capabilities, such as machine learning, IoT sensing, data analytics, and cognitive machines mimicking human intelligence. This journal blends together big-data theories with emerging technologies on smart clouds and exploring supercomputers with new applications.