Ethernet Passive Optical Network (EPON) systems have been deployed widely as a broadband access network solution. Recently, 10Gigabit EPON (10G-EPON) has been investigated as one of the next optical access network solutions. In 10G-EPON system, one of the key technologies is the Dynamic Bandwidth Allocation (DBA) which achieves the high bandwidth efficiency and provides high data throughput for the end users. In this paper, we propose a new DBA algorithm: Adaptive DBA (AD-DBA) which is adaptively switching status-reporting method and traffic monitoring method according to the traffic load and achieves high data throughput and low data transmission delay. Then, we report the evaluation results of proposed algorithm with our 10G-EPON prototype system.