The article suggests the original method for ecological suitability evaluation of the habitat for local populations of Vavilovia formosa (Steven) Al.Fed. in the Republic of Dagestan (Northern Caucasus). Particular attention is paid to the development of methodological issues of studying the state of rare species local populations. The improvement of the methodology for constructing predictive ranges and the expert evaluation procedure of the obtained results is illustrated by the example of the eastern range fragment detailed analysis of V. formosa in the North Caucasus. The research has identified the limiting factors complexes that determine the patterns of local populations spatial distribution on slopes of different exposure, steepness and absolute height in models of different spatial resolution. For the first time, the translation of the initial probability values into a new habitat suitability index has been proposed and implemented. This index allows working with probability values in the form of natural numbers, which greatly facilitated their comparison. Evaluation of predictors by their contribution to predictive models of different spatial resolution convincingly shows the need to build a full-term series of models that will include the entire range of available spatial resolutions – from 1/6 to 1/120 degrees. Only such an approach will allow the researcher to obtain the most meaningful information base for a correct assessment of the contribution of predictors, taking into account the levels of spatial climate data generalization. A promising direction for further research can be considered dis-cretization of predictive values of the habitat suitability index by dividing small climatic areas into even smaller ones, for example, with a dimension of 1/360 degrees in longitude and latitude.