A traffic performance in a tree type multi-hop wireless network of a CSMA/CA method is evaluated easily and highly precisely. A traffic performance evaluation system in the multi-hop wireless network includes: a performance index estimation unit regarding the multi-hop wireless network as a combination of a plurality of single-hop wireless networks and estimating a traffic performance index around each node of the network; and a performance index determination unit determining a traffic performance index of the whole multi-hop wireless network based on an estimation result of all the nodes by the performance index estimation unit.