Ecological footprint is a vital index for measuring whether an area is developing in a sustainable manner. This study calculates and analyzes the ecological footprint of Taiwan from 1994 to 2007. The per capita ecological footprint of Taiwan was 5.09 global hectares in 1994, and increased to 5.52 global hectares in 2005 and 6.54 global hectares in 2007. Based on the 2007 figure an area 42 times the size of Taiwan is needed to sustain the consumption of Taiwan. Moreover, the per capita ecological deficit in Taiwan also worsened during this period, from 3.09 global hectares in 1994 to 3.71 global hectares in 1994 and 4.74 global hectares in 2007, indicating resource overshooting and placing further pressure on the Earth. The calculation of ecological efficiency reveals that the poorest performance occurred in 1997, while performance was improved in 2003.