As demand for large amount of data storage increased with variety and need for speedy access to data their comes in Big Data. Big data come in for data mining and to understand pattern and trend of data. It becomes little bit of impossible to store gigabytes of information so, organisations apprehend to store these large data on cloud, because of processing power and scalability in terms of pay as you use. Due to increasing demand of security for data and access Structures, data owner are not able to store this amount of data on their own without any security infrastructure. In this paper we propose a way of encryption for big data access control.