Abstract: The remote reprogramming of sensor nodes through the wireless channel is a very important function for the efficient management and maintenance of sensor networks.Traditional reprogramming protocols do not provide any security scheme,makes the sensor network vulnerable to some kinds of simple attacks;new secure reprogramming protocols uses asymmetric cryptography schemes needed many computational and memory overheads,which may not be acceptable for resource-constrained wireless sensor nodes.A secure protocol based on the software attestation technology for reprogramming of wireless sensor networks is proposed in this paper;it hides a symmetric key with code attestation running on a legitimate node and a base station separately,and has dynamic characteristics through transmitting a parameter r from the base station to the sensor.This protocol is integrated with existing reprogramming protocol MNP.Simulation results show that the proposed protocol increases the security and reliability of reprogramming at lower communication cost and short delay.