Abstract: We examined the spatial distribution and associations of Ammopiptanthus mongolicus with different recession degrees and at different developmental stages in West Ordos National Nature Reserve in Inner Mongolia, China, with O-ring statistical analysis method. Spatial distribution patterns of A. mongolicus populations varied with different recession degrees, depending on the scale level. Populations with severe and moderate recession degrees performed random distribution at 0-50 m scale, while those with mild recession displayed clumped distribution, and shifted to random distribution with increasing scales. Healthy population showed clumped distribution at the small scale, uniform distribution at the middle scale, and random distribution at the large scale. Spatial distribution patterns of A. mongolicus varied with developmental stages. The population with young and old age classes displayed random distribution at the scale level of 0-50 m, whereas population with young-middle age class showed clumped distribution at the middle scale and random distribution at other scales. The populations with middle age class and middle-old age class all showed clumped distribution at the small scale, but showed uniform distribution with increasing scale and random distribution at the large scale. Moreover, the spatial association of A. mongolicus varied with developmental stages. There was no correlation between the population at the young class and those at different developmental stages at 0-50 m scale. Beginning with the populations at the middle-young class, the associations started to appear with the increase of age class. There was a positive correlation between these high age classes at most scales, whereas there was a negative correlation between the populations of middle class and middle-old class at the 5 m scale.