While “big data” has become a highlighted buzzword since last year, “big data mining”, i.e., mining from big data, has almost immediately followed up as an emerging, interrelated research area. This paper provides an overview of big data mining and discusses the related challenges and the new opportunities. The discussion includes a review of state-of-the-art frameworks and platforms for processing and managing big data as well as the efforts expected on big data mining. We address broad issues related to big data and/or big data mining, and point out opportunities and research topics as they shall duly flesh out. We hope our effort will help reshape the subject area of today’s data mining technology toward solving tomorrow’s bigger challenges emerging in accordance with big data.