[Background] Gully erosion is one of the major forms of soil erosion threatening land resources on the Loess Plateau. Gully development is a threshold-dependent process controlled by a wide range / of factors and vegetation is frequently considered as one of the key factors to control gully erosion. [Methods] In order to give great insight to gully development characteristics since the project of returning cropland to forest (grass) in 1999, 30 small catchments without check dam and 6 catchments with check-dams were selected in Wuqi County of northern Shaanxi province, which is in the second sub- zone of loess hilly region with active gully erosion. Based on two same time phases QuickBird images of 0.61 m-resolution with a 6-year interval and digital elevation model (DEM) with pixel size of 5 m, valley shoulder lines in the studied small catchments were extracted by visual interpretation and the rates of gully area change were estimated with GIS technology. Average vegetation coverage, local slope, upslope drainage area, land uses, and the change rates of gully area from 2007 to 2013 were calculated to assess the factors influencing gully growth. [Results] 1) Annual average growth rate of gully area in all 36 studied catchments was less than 0.5%, with averagely 0.13% in the catchments without check dam and 0.12% in the catchments with check dams. 2) Pearson’s correlation analysis among gully growth rates and the factors influencing gully erosion showed that vegetation coverage on inter-valley was of the most importance with r = 0.619 at significance level of 0.01, followed by proportion of shrub land. The geomorphologic factor ( AS², where S is local slope gradient and A is drainage area), which was considered the predictor of gully initiation, was not related significantly to gully area growth rates owing to high vegetation coverage. 3) The vegetation coverage increased by 28.7% and the proportion of woodland and grassland area increased to 94.5% from 2007 to 2013 in the studied area. Non-linear regression curve between growth rates of gully area and vegetation coverage in 30 catchments without check dam, with R2 was 0.713, indicated that vegetation coverage larger than 60% in inter-valley significantly inhibited the gully erosion. 4) Analysis of variation showed that there was no significant difference of the gully area growth rate between 6 pairs of catchments with and without check dams (with the similar vegetation coverage and geomorphology), indicating that check dam in the area of gully presented no significant effect on the gully development on valley shoulder line. [Conculsions] This study indicates that vegetation restoration owing to the project of returning cropland to forest or grassland reduced gully growth rate significantly, which could provide reference for understanding gully development mechanism and help to select the effective ecological measures to control gully erosion.