In the context of rural transformation and reconstruction and urban-rural integration, production factors such as population, land and capital, continue to flow between urban and rural areas, so rural areas have happened great changes. Accessibility, as the direct medium to drive the change of rural characteristics, has an important impact on rural poverty alleviation and sustainable development. Taking the counties as the basic spatial unit, we examine the spatio-temporal dynamic of rurality and potential accessibility in the Loess Plateau by evaluating the rurality and potential accessibility indexes quantitatively of the 243 counties in the years of 1990, 2000, 2010 and 2015. At the same time, this article analyzes the geographical concentration and the correlation of the rurality and potential accessibility of the Loess Plateau by using the methods of exploratory spatial data analysis and spatial econometric model. The main conclusions are as follows: 1) Rurality indexes of the counties in the Loess Plateau tend to decline, but the difference among 243 counties becomes wider, and the distribution pattern of rurality index presents the pattern of “high in the west and low in the east”; the potential accessibility in Loess Plateau tends to enhanced, but the difference among 243 counties becomes shrinking, and the distribution pattern of potential accessibility—“high in the east and low in the west”—is basically unchanged from 1990 to 2015. 2) The spatial distribution of rurality and accessibility has a strong positive spatial autocorrelation respectively, but the spatial aggregation tends to weaken from 1990 to 2015, and distributes along the line of “Yulin-Qingyang”. Moreover, the rurality’s high-high agglomeration areas are mainly distributed in Liupan Mountainous Area and Luliang Mountainous Area, while the potential accessibility agglomeration areas are mainly distributed in Guanzhong plain, Henan and Shanxi, and gradually extend to Inner Mongolia. What’s more, the increase in accessibility has a negative effect on rurality and this effect becomes enhanced volatility, which verifies the hypothesis that areas with high accessibility is always with weaker rurality, meanwhile, the low accessibility-high rurality types are mainly distributed in Qinghai, Gansu and Ningxia, the high accessibility-low rurality types are mainly distributed in the northeast with a higher economic development. 3) The rurality shows significantly spatial spillover effect, that is significant spatial lag and spatial error spillover effect, which means the rural development in the region will be affected by the surrounding rural area. The improvement of potential accessibility will make the rural population change rate and the primary industry rate decline, while make the agricultural labor productivity, rural per capita net income, and agricultural land productivity increase. What’s more, the accessibility has the greatest impact on agricultural land productivity from 1990 to 2015, but the impact on rural residents' per capita net income enhanced most.
