With the fast progression of digital data exchange in electronic way, security of information is becoming more important in data storage and transmission. Cryptography has come up as a solution which plays a vital role in information security system against malicious attacks. This security system uses some algorithms to scramble data into scribbled text which can be only being decoded or decrypted by party those possesses the associated key. These algorithms consume a significant amount of computing resources such as CPU time, memory and computation time. In this paper a most widely used symmetric encryption techniques i.e. advanced encryption standard (AES) have been implemented using MATLAB software. After the implementing this encryption technique, analysis is done by using a parameter called Avalanche effect. Plaintext and encryption key are mapped in binary code before encryption process. Avalanche Effect is calculated by changing one bit in plaintext keeping the key constant and by changing one bit in encryption key keeping the key constant, Experimental results shows that the proposed algorithm exhibit significant high Avalanche Effect which improves the level of the security.