Abstract: Habitat quality is an important factor affecting regional ecosystem service value and protecting the biodiversity of the earth. Gansu Province is located in the intersection of the three nature areas in China. On the basis of quantitative estimation of the regional habitat quality in Gansu during 2000 to 2018, based on the spectrum change analysis theory and InVEST model, we explored the spatio-temporal differentiation pattern of the regional habitat quality status and its spectrum transformation and change intensity. The results showed that the habitat quality of Gansu Province generally maintained a middle level and improved slightly, showing a step-by-step change from the north to south in the spatial distribution, with the coexistence of both high and low habitat quality. The structure of habitat quality in Gansu Province was stable based on the view of the spectrum transformation, and the spectrum units which did not appear state transition were dominant in quantity. The transition of each other of those spectrum units which had occurred transition of the habitat quality, such as higher  lower, higher  high, higher  low was most obvious, with the spatial distribution in aggregation. The change intensity of habitat quality in Gansu Province presented a general tendency with active in the north and moderate in the south, presenting as active intensity area, complex intensity area, moderate intensity area, and slight intensity area from the north to south.

Key words: habitat quality, spatial and temporal difference, spectrum feature, InVEST model, intersection of three nature areas