Abstract-For the verification of authorized users in computer systems, various text based or biometrics methods are used. But these methods have some drawbacks. It is difficult to remember and recall the textual i.e. alphanumeric passwords. To avoid this drawback users prefer to create effortless, short, easy and insecure passwords which are easily guessable by hacker and this makes the system more vulnerable to attacks. On other hand, verification mechanisms based on biometrics offers security to a good extents. But they are quite luxurious for implementation. Cost becomes a key factor in the case of biometrics. Also any injury to the body part used in biometric authorization results in denial of access or performance issues. Graphical password provides another way by providing passwords that are more protected and unforgettable in a reasonable price. In this system, user clicks on images instead of typing passwords for accessing the system. This paper describes and examines usability and security of graphical password mechanism for authentication using graphical passwords. Proposed system describes characteristics for security and performed empirical study comparing Graphical password mechanism with Biometric passwords and alphanumeric password.