We have developed a privacy-aware user tracking system that can track users by using their footprint data measured across spatially disjoint pressure sensor sheets. The main task in the system is to recognize correspondence between footprints measured across pressure sensor sheets, i.e., it needs to recognize a single user walking across pressure sensor sheets as an instance and different users as different ones. In this paper, we propose a footprint matching method designed for walking users. It mainly consists of two steps: i.e., footprint averaging and similarity calculating, in order to handle footprint data recorded as a time series for a walking user. Moreover, we have conducted a basic evaluation to confirm the effectiveness of the proposed footprint matching method. The result shows that the matching performance can achieve 78%.