Abstract: With the problem of QoS management for wireless multimedia sensor networks (WMSNs), a measurement-based QoS route mechanism is suggested. First the end-to-end QoS metrics are obtained through distributed measurement, second the hop-by-hop link QoS dynamics are estimated with NT(network tomography)model, and then feed back to the network layer route algorithm. An improved ant colony algorithm (ACA) is employed and the QoS metrics act as the heuristic factor. Simulation results show that this mechanism outperforms traditional algorithms in terms of QoS rating.