Efficient implementation of block cipher is important on the way to achieving high efficiency with good understand ability. Numerous number of block cipher including Advance Encryption Standard (AES) have been implemented using different platform. However, the understanding of the AES algorithm step by step is very complicated. This paper presents the implementation of AES algorithm and explains Avalanche effect with the help of Avalanche test result. In this paper, the authors use Xilinx ISE 9.1i platform in algorithm development and ModelSim SE 6.3f platform for results confirmation and computation.