Wireless sensor networks are being deployed for some practical applications and their se-curity has received considerable attention.It is an important challenge to find out suitable keyagreement and encryption scheme for wireless sensor networks due to limitations of the power,com-putation capability and storage resources.In this paper,an efficient key agreement and encryptionscheme for wireless sensor networks is presented.Results of analysis and simulations among the pro-posed scheme and other schemes show that the proposed scheme has some advantages in terms ofenergy consumption,computation requirement,storage requirement and security. Wireless sensor networks are being deployed for some practical applications and their se-curity has received considerable attention. It is an important challenge to find out suitable key agreement and encryption schemes for wireless sensor networks due to limitations of the power, com-putation capability and storage resources. This paper, an efficient key agreement and encryptionscheme for wireless sensor networks is presented. Results of analysis and simulations among the pro-posed scheme and other schemes show that the proposed scheme has some advantages in terms of energy consumption, computation requirement, storage requirement and security.