Abstract: To explore the adaptability of conservation tillage in the Loess Plateau semi-arid areas of Gansu Province, a conservation tillage experiment was conducted for 2001 ~ 2005 and the Analytic Hierarchy Process (AHP) used to evaluate the economic and ecological suitability of five conservation tillage methods. The economic and ecological adaptability evaluation shows that no-tillage with straw cover (NTS) is the best among the tillage methods investigated. NTS adaptability ratio (PI) is far higher than the other tillage methods, ranging from 0.76 to 0.84 , which is 2 ~ 2.5 times ordinary tillage (T), showing that NTS treatment is more adaptable to the local ecology. PIs for NTS, no-tillage (NT) and no-tillage with plastic cover (NTP) are higher than that for tillage with straw cover (TS), T and tillage with plastic cover (TP). This implies that the adaptability of NTS, NT and NTP is better than that of TS, T and TP. Hence adopting NTS not only increases crop yield or reduces total input, but also enhances sustained development of agriculture in the Loess Plateau semi-arid areas of Gansu Province.