The emerging paradigm of cloud computing provides a new way to address the constraints of limited energy, capabilities, and resources. Researchers and practitioners have embraced cloud computing as a new approach that has the potential for a profound impact in our daily life and world economy. Click on the image and go back to homepage. About 40% data globally would be related to cloud computing by 2020, as estimated by IDC. The large volume of data has big complexity and variety. To avoid system fragility and defend against vulnerabilities exploration from cyber attacker, various security techniques and tools have been developed for Big Data on cloud. There are two important aspects of Big Data Security, especially in cloud computing environment. One is how to protect big data, the other is how to using big data analytic technique to enhance security of the whole system.