This paper aims to examine changes in livelihood structures over a 40-year period (1975-2014) in a mountainous village in the North Toraja region of Indonesia., by semi-structured interview survey and network analysis of the field interview data. To detect the time-series change of the local peoples’ livelihood situation, the network centrality index was calculated for each livelihood items. By the inspection of the deference of centrality, 3 periods (1979-1980, 1999-2000 and 2009-2010) yielded significance by paired t-test. The results indicate a recent rural livelihood diversification trend. Furthermore the change point of time-series centrality overlapped with a period of road building and irrigation installation.