In traditional authentication system Password, PIN and Signature are used as single source for identification of persons. But these can be lost, stolen or subjected to spoofing attack. In biometric authentication system a person is identified through physical traits or behavioural traits. These traits are fingerprint, palm-print, face, iris, signature, speech and so on. Biometric authentication systems are more robust, secure, and they do not require carrying of things such as smart cards which are used in the standard authentication systems. The prime aim of this thesis is to developed a biometric authentication system with different modalities like uni-modal, bi-modal, and tri-modal by combining physical and behavioural traits and validate them experimentally. Various approaches have been studied for development of biometic authentication system. Single source biometic and multimodal biometric authentication systems have been studied.