Wireless Sensor Network consists of spatially distributed autonomous sensors to monitor environmental or physical conditions and has many practical applications. WSNs are of interest to adversaries and they become susceptible to some types of attacks since they are deployed in open and unprotected environments. Due to the limited resources of WSNs, it is challenging to incorporate basic security features such as authentication, key distribution and privacy in WSNs. But, trust management that models the trust on the behavior of elements of the network , can be especially useful for a sensor network environment to enhance security. Trust management schemes that are targeted at sensor networks need to be lightweight in terms of computational and communication requirements, yet powerful in terms of flexibility in managing trust between nodes of heterogeneous deployments . This paper surveys various trust management schemes proposed for wireless sensor network.