Packet loss may cause the degradation of network and application performance. This paper proposes a passive measurement method called LTS to estimate end-to-end path packet loss ratio for the two segments of the path divided by the monitor node. This method can estimate the packet loss ration of each segment and infer loss ratios based on IP headers identification field, TCP headers sequence number and packets interval. The segment estimation packet loss method can be useful to evaluate the performance of core network or internet work if the monitor is put in the border of a network. The algorithm is evaluated to use a test bed simulation measurement, and is analyzed reordering ratios and loss ratios based on the traces collected from the CERNET backbone links.